by steps
000000 000000
000000
7f7f7f 7f7f7f
7f7f7f
00007f 00007f
00007f
0000ff 0000ff
0000ff
007f00 007f00
007f00
007f7f 007f7f
007f7f
738080 738080
738080
007fff 007fff
007fff
00ff00 00ff00
00ff00
00ff7f 00ff7f
00ff7f
678181 678181
678181
00ffff 00ffff
00ffff
7f0000 7f0000
7f0000
7f007f 7f007f
7f007f
5b8282 5b8282
5b8282
7f00ff 7f00ff
7f00ff
7f7f00 7f7f00
7f7f00
4f8383 4f8383
4f8383
7f7fff 7f7fff
7f7fff
7fff00 7fff00
7fff00
7fff7f 7fff7f
7fff7f
7fffff 7fffff
7fffff
438484 438484
438484
ff0000 ff0000
ff0000
ff007f ff007f
ff007f
ff00ff ff00ff
ff00ff
378585 378585
378585
ff7f00 ff7f00
ff7f00
ff7f7f ff7f7f
ff7f7f
ff7fff ff7fff
ff7fff
2b8686 2b8686
2b8686
ffff00 ffff00
ffff00
ffff7f ffff7f
ffff7f
ffffff ffffff
ffffff
1f8787 1f8787
1f8787