by steps
000000 000000
000000
ffffff ffffff
ffffff
00007f 00007f
00007f
0000ff 0000ff
0000ff
007f00 007f00
007f00
007f7f 007f7f
007f7f
fefafc fefafc
fefafc
007fff 007fff
007fff
00ff00 00ff00
00ff00
00ff7f 00ff7f
00ff7f
fef5f9 fef5f9
fef5f9
00ffff 00ffff
00ffff
7f0000 7f0000
7f0000
7f007f 7f007f
7f007f
fef1f6 fef1f6
fef1f6
7f00ff 7f00ff
7f00ff
7f7f00 7f7f00
7f7f00
7f7f7f 7f7f7f
7f7f7f
feecf4 feecf4
feecf4
7f7fff 7f7fff
7f7fff
7fff00 7fff00
7fff00
7fff7f 7fff7f
7fff7f
7fffff 7fffff
7fffff
fee7f1 fee7f1
fee7f1
ff0000 ff0000
ff0000
ff007f ff007f
ff007f
ff00ff ff00ff
ff00ff
fee3ee fee3ee
fee3ee
ff7f00 ff7f00
ff7f00
ff7f7f ff7f7f
ff7f7f
ff7fff ff7fff
ff7fff
fedeeb fedeeb
fedeeb
ffff00 ffff00
ffff00
ffff7f ffff7f
ffff7f
fedae9 fedae9
fedae9