ClassicLunatic.com - USTC Supply Snapshots

Date / Time	Circulating Supply	Difference	Total Supply	Difference	Comm. Pool	USD per coin	Block
Dec 19, 2022, 16:43	9,805,006,845	-29	9,805,006,845	-30	766,642	$0.020824	10,727,277
Dec 19, 2022, 16:42	9,805,006,874	-1	9,805,006,875		766,633	$0.020800	10,727,267
Dec 19, 2022, 16:41	9,805,006,875	-11	9,805,006,875	-11	766,631	$0.020795	10,727,257
Dec 19, 2022, 16:40	9,805,006,886	-23	9,805,006,886	-23	766,627	$0.020747	10,727,247
Dec 19, 2022, 16:39	9,805,006,909	-13	9,805,006,909	-13	766,626	$0.020750	10,727,238
Dec 19, 2022, 16:38	9,805,006,922	-20	9,805,006,922	-20	766,615	$0.020681	10,727,228
Dec 19, 2022, 16:37	9,805,006,942	-16	9,805,006,942	-16	766,526	$0.020724	10,727,218
Dec 19, 2022, 16:36	9,805,006,958	-18	9,805,006,958		766,525	$0.020750	10,727,208
Dec 19, 2022, 16:35	9,805,006,976		9,805,006,958	-18	766,525	$0.020748	10,727,198
Dec 19, 2022, 16:34	9,805,006,976	-2	9,805,006,976	-5	766,524	$0.020800	10,727,188
Dec 19, 2022, 16:33	9,805,006,978	-3	9,805,006,981		766,523	$0.020858	10,727,179
Dec 19, 2022, 16:32	9,805,006,981	-43	9,805,006,981	-43	766,521	$0.020829	10,727,169
Dec 19, 2022, 16:31	9,805,007,024		9,805,007,024		766,519	$0.020942	10,727,159
Dec 19, 2022, 16:30	9,805,007,024	-10	9,805,007,024	-10	766,519	$0.020953	10,727,149
Dec 19, 2022, 16:29	9,805,007,034	-10	9,805,007,034	-32	766,515	$0.020955	10,727,140
Dec 19, 2022, 16:28	9,805,007,044	-22	9,805,007,066		766,513	$0.020903	10,727,131
Dec 19, 2022, 16:27	9,805,007,066		9,805,007,066		766,512	$0.020926	10,727,121
Dec 19, 2022, 16:26	9,805,007,066	-1	9,805,007,066	-1	766,503	$0.020941	10,727,111
Dec 19, 2022, 16:25	9,805,007,067	-199	9,805,007,067	-209	766,501	$0.020900	10,727,101
Dec 19, 2022, 16:24	9,805,007,266	-10	9,805,007,276		766,498	$0.021089	10,727,091
Dec 19, 2022, 16:23	9,805,007,276		9,805,007,276		766,483	$0.021136	10,727,082
Dec 19, 2022, 16:22	9,805,007,276		9,805,007,276		766,481	$0.021100	10,727,072
Dec 19, 2022, 16:21	9,805,007,276		9,805,007,276		766,480	$0.021081	10,727,062
Dec 19, 2022, 16:20	9,805,007,276	-3	9,805,007,276	-3	766,479	$0.021100	10,727,052
Dec 19, 2022, 16:19	9,805,007,279		9,805,007,279		766,476	$0.021098	10,727,043
Dec 19, 2022, 16:18	9,805,007,279	-5	9,805,007,279	-5	766,476	$0.021056	10,727,034
Dec 19, 2022, 16:17	9,805,007,284		9,805,007,284	-3	766,474	$0.020998	10,727,024
Dec 19, 2022, 16:16	9,805,007,284	-3	9,805,007,287		766,473	$0.021034	10,727,014
Dec 19, 2022, 16:15	9,805,007,287	-9	9,805,007,287	-2	766,472	$0.021033	10,727,004
Dec 19, 2022, 16:14	9,805,007,296		9,805,007,289	-7	766,472	$0.021039	10,726,994
Dec 19, 2022, 16:13	9,805,007,296	-4	9,805,007,296	-3	766,469	$0.021039	10,726,985
Dec 19, 2022, 16:12	9,805,007,300		9,805,007,299	-1	766,467	$0.020984	10,726,975
Dec 19, 2022, 16:11	9,805,007,300		9,805,007,300		766,466	$0.021015	10,726,965
Dec 19, 2022, 16:10	9,805,007,300	-2	9,805,007,300	-2	766,462	$0.021015	10,726,956
Dec 19, 2022, 16:09	9,805,007,302		9,805,007,302		766,461	$0.021018	10,726,946
Dec 19, 2022, 16:08	9,805,007,302	-4	9,805,007,302	-6	766,443	$0.021031	10,726,936
Dec 19, 2022, 16:07	9,805,007,306	-152	9,805,007,308		766,442	$0.021038	10,726,926
Dec 19, 2022, 16:06	9,805,007,458	-5	9,805,007,308	-155	766,419	$0.021001	10,726,916
Dec 19, 2022, 16:05	9,805,007,463	-39	9,805,007,463	-39	766,418	$0.021027	10,726,907
Dec 19, 2022, 16:04	9,805,007,502	-3	9,805,007,502	-3	766,418	$0.021027	10,726,897
Dec 19, 2022, 16:03	9,805,007,505	-34	9,805,007,505	-34	766,416	$0.021050	10,726,887
Dec 19, 2022, 16:02	9,805,007,539	-1	9,805,007,539	-1	766,413	$0.021092	10,726,877
Dec 19, 2022, 16:01	9,805,007,540	-1	9,805,007,540	-1	766,412	$0.021100	10,726,867
Dec 19, 2022, 16:00	9,805,007,541		9,805,007,541		766,411	$0.021108	10,726,858
Dec 19, 2022, 15:59	9,805,007,541	-2	9,805,007,541	-2	766,407	$0.021060	10,726,848
Dec 19, 2022, 15:58	9,805,007,543		9,805,007,543		766,405	$0.021119	10,726,838
Dec 19, 2022, 15:57	9,805,007,543	-32	9,805,007,543	-32	766,405	$0.021113	10,726,829
Dec 19, 2022, 15:56	9,805,007,575	-1	9,805,007,575	-1	766,404	$0.021161	10,726,819
Dec 19, 2022, 15:55	9,805,007,576	-1	9,805,007,576	-1	766,402	$0.021129	10,726,809
Dec 19, 2022, 15:54	9,805,007,577	-1	9,805,007,577	-1	766,401	$0.021144	10,726,799
Dec 19, 2022, 15:53	9,805,007,578	-1	9,805,007,578	-1	766,400	$0.021144	10,726,789
Dec 19, 2022, 15:52	9,805,007,579		9,805,007,579		766,399	$0.021163	10,726,779
Dec 19, 2022, 15:51	9,805,007,579		9,805,007,579		766,398	$0.021163	10,726,770
Dec 19, 2022, 15:50	9,805,007,579		9,805,007,579		766,396	$0.021143	10,726,760
Dec 19, 2022, 15:49	9,805,007,579	-1	9,805,007,579	-2	766,395	$0.021104	10,726,750
Dec 19, 2022, 15:48	9,805,007,580	-1	9,805,007,581		766,393	$0.021129	10,726,740
Dec 19, 2022, 15:47	9,805,007,581	-1	9,805,007,581	-1	766,392	$0.021107	10,726,730
Dec 19, 2022, 15:46	9,805,007,582		9,805,007,582		766,391	$0.021166	10,726,720
Dec 19, 2022, 15:45	9,805,007,582	-2	9,805,007,582	-2	766,389	$0.021173	10,726,711
Dec 19, 2022, 15:44	9,805,007,584	-24	9,805,007,584	-24	766,388	$0.021193	10,726,701
Dec 19, 2022, 15:43	9,805,007,608	-6	9,805,007,608	-6	766,388	$0.021200	10,726,691
Dec 19, 2022, 15:42	9,805,007,614		9,805,007,614		766,387	$0.021200	10,726,682
Dec 19, 2022, 15:41	9,805,007,614		9,805,007,614		766,387	$0.021203	10,726,671
Dec 19, 2022, 15:40	9,805,007,614		9,805,007,614		766,387	$0.021204	10,726,662
Dec 19, 2022, 15:39	9,805,007,614		9,805,007,614		766,386	$0.021251	10,726,652
Dec 19, 2022, 15:38	9,805,007,614		9,805,007,614		766,385	$0.021280	10,726,642
Dec 19, 2022, 15:37	9,805,007,614	-1	9,805,007,614	-1	766,384	$0.021280	10,726,633
Dec 19, 2022, 15:36	9,805,007,615	-18	9,805,007,615	-18	766,382	$0.021233	10,726,623
Dec 19, 2022, 15:35	9,805,007,633	-1	9,805,007,633	-1	766,381	$0.021212	10,726,613
Dec 19, 2022, 15:34	9,805,007,634	-1	9,805,007,634	-1	766,376	$0.021221	10,726,604
Dec 19, 2022, 15:33	9,805,007,635		9,805,007,635		766,375	$0.021223	10,726,594
Dec 19, 2022, 15:32	9,805,007,635	-3	9,805,007,635	-3	766,374	$0.021272	10,726,584
Dec 19, 2022, 15:31	9,805,007,638		9,805,007,638		766,371	$0.021280	10,726,575
Dec 19, 2022, 15:30	9,805,007,638	-2	9,805,007,638	-2	766,369	$0.021274	10,726,565
Dec 19, 2022, 15:29	9,805,007,640	-130	9,805,007,640	-130	766,367	$0.021230	10,726,556
Dec 19, 2022, 15:28	9,805,007,770		9,805,007,770		766,366	$0.021275	10,726,546
Dec 19, 2022, 15:27	9,805,007,770	-1	9,805,007,770		766,366	$0.021285	10,726,536
Dec 19, 2022, 15:26	9,805,007,771		9,805,007,770	-1	766,365	$0.021285	10,726,526
Dec 19, 2022, 15:25	9,805,007,771	-1	9,805,007,771	-1	766,363	$0.021275	10,726,517
Dec 19, 2022, 15:24	9,805,007,772		9,805,007,772		766,363	$0.021220	10,726,507
Dec 19, 2022, 15:23	9,805,007,772		9,805,007,772		766,361	$0.021201	10,726,497
Dec 19, 2022, 15:22	9,805,007,772	-75	9,805,007,772	-37	766,359	$0.021246	10,726,487
Dec 19, 2022, 15:21	9,805,007,847		9,805,007,809	-41	766,358	$0.021282	10,726,478
Dec 19, 2022, 15:20	9,805,007,847	-3	9,805,007,850		766,357	$0.021297	10,726,468
Dec 19, 2022, 15:19	9,805,007,850	-376	9,805,007,850	-376	766,356	$0.021236	10,726,458
Dec 19, 2022, 15:18	9,805,008,226	-378	9,805,008,226	-378	766,354	$0.021226	10,726,448
Dec 19, 2022, 15:17	9,805,008,604		9,805,008,604		766,353	$0.021260	10,726,438
Dec 19, 2022, 15:16	9,805,008,604	-1	9,805,008,604	-1	766,352	$0.021231	10,726,429
Dec 19, 2022, 15:15	9,805,008,605	-16	9,805,008,605	-9	766,350	$0.021192	10,726,419
Dec 19, 2022, 15:14	9,805,008,621		9,805,008,614	-7	766,343	$0.021180	10,726,409
Dec 19, 2022, 15:13	9,805,008,621		9,805,008,621		766,342	$0.021147	10,726,399
Dec 19, 2022, 15:12	9,805,008,621	-4	9,805,008,621	-4	766,340	$0.021111	10,726,390
Dec 19, 2022, 15:11	9,805,008,625	-31	9,805,008,625	-31	766,339	$0.021154	10,726,379
Dec 19, 2022, 15:10	9,805,008,656	-2	9,805,008,656	-2	766,333	$0.021154	10,726,370
Dec 19, 2022, 15:09	9,805,008,658		9,805,008,658		766,329	$0.021207	10,726,360
Dec 19, 2022, 15:08	9,805,008,658	-2	9,805,008,658	-2	766,327	$0.021207	10,726,350
Dec 19, 2022, 15:07	9,805,008,660	-10	9,805,008,660	-10	766,327	$0.021234	10,726,340
Dec 19, 2022, 15:06	9,805,008,670	-38	9,805,008,670	-38	766,326	$0.021221	10,726,331
Dec 19, 2022, 15:05	9,805,008,708		9,805,008,708		766,325	$0.021261	10,726,321
Dec 19, 2022, 15:04	9,805,008,708	-14	9,805,008,708	-14	766,324	$0.021200	10,726,311

Date / Time

Circulating Supply

Difference

Total Supply

Difference

Comm. Pool

USD per coin

Block

Dec 19, 2022, 16:43

9,805,006,845

-29

9,805,006,845

-30

766,642

$0.020824

10,727,277

Dec 19, 2022, 16:42

9,805,006,874

-1

9,805,006,875

766,633

$0.020800

10,727,267

Dec 19, 2022, 16:41

9,805,006,875

-11

9,805,006,875

-11

766,631

$0.020795

10,727,257

Dec 19, 2022, 16:40

9,805,006,886

-23

9,805,006,886

-23

766,627

$0.020747

10,727,247

Dec 19, 2022, 16:39

9,805,006,909

-13

9,805,006,909

-13

766,626

$0.020750

10,727,238

Dec 19, 2022, 16:38

9,805,006,922

-20

9,805,006,922

-20

766,615

$0.020681

10,727,228

Dec 19, 2022, 16:37

9,805,006,942

-16

9,805,006,942

-16

766,526

$0.020724

10,727,218

Dec 19, 2022, 16:36

9,805,006,958

-18

9,805,006,958

766,525

$0.020750

10,727,208

Dec 19, 2022, 16:35

9,805,006,976

9,805,006,958

-18

766,525

$0.020748

10,727,198

Dec 19, 2022, 16:34

9,805,006,976

-2

9,805,006,976

-5

766,524

$0.020800

10,727,188

Dec 19, 2022, 16:33

9,805,006,978

-3

9,805,006,981

766,523

$0.020858

10,727,179

Dec 19, 2022, 16:32

9,805,006,981

-43

9,805,006,981

-43

766,521

$0.020829

10,727,169

Dec 19, 2022, 16:31

9,805,007,024

766,519

$0.020942

10,727,159

Dec 19, 2022, 16:30

9,805,007,024

-10

9,805,007,024

-10

766,519

$0.020953

10,727,149

Dec 19, 2022, 16:29

9,805,007,034

-10

9,805,007,034

-32

766,515

$0.020955

10,727,140

Dec 19, 2022, 16:28

9,805,007,044

-22

9,805,007,066

766,513

$0.020903

10,727,131

Dec 19, 2022, 16:27

9,805,007,066

766,512

$0.020926

10,727,121

Dec 19, 2022, 16:26

9,805,007,066

-1

9,805,007,066

-1

766,503

$0.020941

10,727,111

Dec 19, 2022, 16:25

9,805,007,067

-199

9,805,007,067

-209

766,501

$0.020900

10,727,101

Dec 19, 2022, 16:24

9,805,007,266

-10

9,805,007,276

766,498

$0.021089

10,727,091

Dec 19, 2022, 16:23

9,805,007,276

766,483

$0.021136

10,727,082

Dec 19, 2022, 16:22

9,805,007,276

766,481

$0.021100

10,727,072

Dec 19, 2022, 16:21

9,805,007,276

766,480

$0.021081

10,727,062

Dec 19, 2022, 16:20

9,805,007,276

-3

9,805,007,276

-3

766,479

$0.021100

10,727,052

Dec 19, 2022, 16:19

9,805,007,279

766,476

$0.021098

10,727,043

Dec 19, 2022, 16:18

9,805,007,279

-5

9,805,007,279

-5

766,476

$0.021056

10,727,034

Dec 19, 2022, 16:17

9,805,007,284

-3

766,474

$0.020998

10,727,024

Dec 19, 2022, 16:16

9,805,007,284

-3

9,805,007,287

766,473

$0.021034

10,727,014

Dec 19, 2022, 16:15

9,805,007,287

-9

9,805,007,287

-2

766,472

$0.021033

10,727,004

Dec 19, 2022, 16:14

9,805,007,296

9,805,007,289

-7

766,472

$0.021039

10,726,994

Dec 19, 2022, 16:13

9,805,007,296

-4

9,805,007,296

-3

766,469

$0.021039

10,726,985

Dec 19, 2022, 16:12

9,805,007,300

9,805,007,299

-1

766,467

$0.020984

10,726,975

Dec 19, 2022, 16:11

9,805,007,300

766,466

$0.021015

10,726,965

Dec 19, 2022, 16:10

9,805,007,300

-2

9,805,007,300

-2

766,462

$0.021015

10,726,956

Dec 19, 2022, 16:09

9,805,007,302

766,461

$0.021018

10,726,946

Dec 19, 2022, 16:08

9,805,007,302

-4

9,805,007,302

-6

766,443

$0.021031

10,726,936

Dec 19, 2022, 16:07

9,805,007,306

-152

9,805,007,308

766,442

$0.021038

10,726,926

Dec 19, 2022, 16:06

9,805,007,458

-5

9,805,007,308

-155

766,419

$0.021001

10,726,916

Dec 19, 2022, 16:05

9,805,007,463

-39

9,805,007,463

-39

766,418

$0.021027

10,726,907

Dec 19, 2022, 16:04

9,805,007,502

-3

9,805,007,502

-3

766,418

$0.021027

10,726,897

Dec 19, 2022, 16:03

9,805,007,505

-34

9,805,007,505

-34

766,416

$0.021050

10,726,887

Dec 19, 2022, 16:02

9,805,007,539

-1

9,805,007,539

-1

766,413

$0.021092

10,726,877

Dec 19, 2022, 16:01

9,805,007,540

-1

9,805,007,540

-1

766,412

$0.021100

10,726,867

Dec 19, 2022, 16:00

9,805,007,541

766,411

$0.021108

10,726,858

Dec 19, 2022, 15:59

9,805,007,541

-2

9,805,007,541

-2

766,407

$0.021060

10,726,848

Dec 19, 2022, 15:58

9,805,007,543

766,405

$0.021119

10,726,838

Dec 19, 2022, 15:57

9,805,007,543

-32

9,805,007,543

-32

766,405

$0.021113

10,726,829

Dec 19, 2022, 15:56

9,805,007,575

-1

9,805,007,575

-1

766,404

$0.021161

10,726,819

Dec 19, 2022, 15:55

9,805,007,576

-1

9,805,007,576

-1

766,402

$0.021129

10,726,809

Dec 19, 2022, 15:54

9,805,007,577

-1

9,805,007,577

-1

766,401

$0.021144

10,726,799

Dec 19, 2022, 15:53

9,805,007,578

-1

9,805,007,578

-1

766,400

$0.021144

10,726,789

Dec 19, 2022, 15:52

9,805,007,579

766,399

$0.021163

10,726,779

Dec 19, 2022, 15:51

9,805,007,579

766,398

$0.021163

10,726,770

Dec 19, 2022, 15:50

9,805,007,579

766,396

$0.021143

10,726,760

Dec 19, 2022, 15:49

9,805,007,579

-1

9,805,007,579

-2

766,395

$0.021104

10,726,750

Dec 19, 2022, 15:48

9,805,007,580

-1

9,805,007,581

766,393

$0.021129

10,726,740

Dec 19, 2022, 15:47

9,805,007,581

-1

9,805,007,581

-1

766,392

$0.021107

10,726,730

Dec 19, 2022, 15:46

9,805,007,582

766,391

$0.021166

10,726,720

Dec 19, 2022, 15:45

9,805,007,582

-2

9,805,007,582

-2

766,389

$0.021173

10,726,711

Dec 19, 2022, 15:44

9,805,007,584

-24

9,805,007,584

-24

766,388

$0.021193

10,726,701

Dec 19, 2022, 15:43

9,805,007,608

-6

9,805,007,608

-6

766,388

$0.021200

10,726,691

Dec 19, 2022, 15:42

9,805,007,614

766,387

$0.021200

10,726,682

Dec 19, 2022, 15:41

9,805,007,614

766,387

$0.021203

10,726,671

Dec 19, 2022, 15:40

9,805,007,614

766,387

$0.021204

10,726,662

Dec 19, 2022, 15:39

9,805,007,614

766,386

$0.021251

10,726,652

Dec 19, 2022, 15:38

9,805,007,614

766,385

$0.021280

10,726,642

Dec 19, 2022, 15:37

9,805,007,614

-1

9,805,007,614

-1

766,384

$0.021280

10,726,633

Dec 19, 2022, 15:36

9,805,007,615

-18

9,805,007,615

-18

766,382

$0.021233

10,726,623

Dec 19, 2022, 15:35

9,805,007,633

-1

9,805,007,633

-1

766,381

$0.021212

10,726,613

Dec 19, 2022, 15:34

9,805,007,634

-1

9,805,007,634

-1

766,376

$0.021221

10,726,604

Dec 19, 2022, 15:33

9,805,007,635

766,375

$0.021223

10,726,594

Dec 19, 2022, 15:32

9,805,007,635

-3

9,805,007,635

-3

766,374

$0.021272

10,726,584

Dec 19, 2022, 15:31

9,805,007,638

766,371

$0.021280

10,726,575

Dec 19, 2022, 15:30

9,805,007,638

-2

9,805,007,638

-2

766,369

$0.021274

10,726,565

Dec 19, 2022, 15:29

9,805,007,640

-130

9,805,007,640

-130

766,367

$0.021230

10,726,556

Dec 19, 2022, 15:28

9,805,007,770

766,366

$0.021275

10,726,546

Dec 19, 2022, 15:27

9,805,007,770

-1

9,805,007,770

766,366

$0.021285

10,726,536

Dec 19, 2022, 15:26

9,805,007,771

9,805,007,770

-1

766,365

$0.021285

10,726,526

Dec 19, 2022, 15:25

9,805,007,771

-1

9,805,007,771

-1

766,363

$0.021275

10,726,517

Dec 19, 2022, 15:24

9,805,007,772

766,363

$0.021220

10,726,507

Dec 19, 2022, 15:23

9,805,007,772

766,361

$0.021201

10,726,497

Dec 19, 2022, 15:22

9,805,007,772

-75

9,805,007,772

-37

766,359

$0.021246

10,726,487

Dec 19, 2022, 15:21

9,805,007,847

9,805,007,809

-41

766,358

$0.021282

10,726,478

Dec 19, 2022, 15:20

9,805,007,847

-3

9,805,007,850

766,357

$0.021297

10,726,468

Dec 19, 2022, 15:19

9,805,007,850

-376

9,805,007,850

-376

766,356

$0.021236

10,726,458

Dec 19, 2022, 15:18

9,805,008,226

-378

9,805,008,226

-378

766,354

$0.021226

10,726,448

Dec 19, 2022, 15:17

9,805,008,604

766,353

$0.021260

10,726,438

Dec 19, 2022, 15:16

9,805,008,604

-1

9,805,008,604

-1

766,352

$0.021231

10,726,429

Dec 19, 2022, 15:15

9,805,008,605

-16

9,805,008,605

-9

766,350

$0.021192

10,726,419

Dec 19, 2022, 15:14

9,805,008,621

9,805,008,614

-7

766,343

$0.021180

10,726,409

Dec 19, 2022, 15:13

9,805,008,621

766,342

$0.021147

10,726,399

Dec 19, 2022, 15:12

9,805,008,621

-4

9,805,008,621

-4

766,340

$0.021111

10,726,390

Dec 19, 2022, 15:11

9,805,008,625

-31

9,805,008,625

-31

766,339

$0.021154

10,726,379

Dec 19, 2022, 15:10

9,805,008,656

-2

9,805,008,656

-2

766,333

$0.021154

10,726,370

Dec 19, 2022, 15:09

9,805,008,658

766,329

$0.021207

10,726,360

Dec 19, 2022, 15:08

9,805,008,658

-2

9,805,008,658

-2

766,327

$0.021207

10,726,350

Dec 19, 2022, 15:07

9,805,008,660

-10

9,805,008,660

-10

766,327

$0.021234

10,726,340

Dec 19, 2022, 15:06

9,805,008,670

-38

9,805,008,670

-38

766,326

$0.021221

10,726,331

Dec 19, 2022, 15:05

9,805,008,708

766,325

$0.021261

10,726,321

Dec 19, 2022, 15:04

9,805,008,708

-14

9,805,008,708

-14

766,324

$0.021200

10,726,311

The difference cells relate to the supply cells to the left. The figure can be positive, negative or zero. The difference is calculated as the difference between the supply to the left of it at the given time snapshot and the supply column above it. In other words, how much the supply has gone up or down in that time period. On page 1, the top difference cell shows the difference during the currrent time period and the next to appear. This row is higlighted to show this is ongoing. Other columns show a snapshot of data taken at the given day and time in the far left column. All times shown are GMT (Greenwich Mean Time). To highlight rows just tap or click on the row(s) to cycle background colours.