by steps
000000 000000
000000
7f0000 7f0000
7f0000
00007f 00007f
00007f
0000ff 0000ff
0000ff
007f00 007f00
007f00
007f7f 007f7f
007f7f
7f150f 7f150f
7f150f
007fff 007fff
007fff
00ff00 00ff00
00ff00
00ff7f 00ff7f
00ff7f
7f2a1f 7f2a1f
7f2a1f
00ffff 00ffff
00ffff
7f007f 7f007f
7f007f
803f2f 803f2f
803f2f
7f00ff 7f00ff
7f00ff
7f7f00 7f7f00
7f7f00
7f7f7f 7f7f7f
7f7f7f
80553f 80553f
80553f
7f7fff 7f7fff
7f7fff
7fff00 7fff00
7fff00
7fff7f 7fff7f
7fff7f
7fffff 7fffff
7fffff
806a4f 806a4f
806a4f
ff0000 ff0000
ff0000
ff007f ff007f
ff007f
ff00ff ff00ff
ff00ff
817f5f 817f5f
817f5f
ff7f00 ff7f00
ff7f00
ff7f7f ff7f7f
ff7f7f
ff7fff ff7fff
ff7fff
81946f 81946f
81946f
ffff00 ffff00
ffff00
ffff7f ffff7f
ffff7f
ffffff ffffff
ffffff
82aa7f 82aa7f
82aa7f