by steps
000000 000000
000000
0000ff 0000ff
0000ff
00007f 00007f
00007f
007f00 007f00
007f00
007f7f 007f7f
007f7f
0f01ff 0f01ff
0f01ff
007fff 007fff
007fff
00ff00 00ff00
00ff00
00ff7f 00ff7f
00ff7f
1f03ff 1f03ff
1f03ff
00ffff 00ffff
00ffff
7f0000 7f0000
7f0000
7f007f 7f007f
7f007f
2f05ff 2f05ff
2f05ff
7f00ff 7f00ff
7f00ff
7f7f00 7f7f00
7f7f00
7f7f7f 7f7f7f
7f7f7f
3f07ff 3f07ff
3f07ff
7f7fff 7f7fff
7f7fff
7fff00 7fff00
7fff00
7fff7f 7fff7f
7fff7f
7fffff 7fffff
7fffff
4f08ff 4f08ff
4f08ff
ff0000 ff0000
ff0000
ff007f ff007f
ff007f
ff00ff ff00ff
ff00ff
5f0aff 5f0aff
5f0aff
ff7f00 ff7f00
ff7f00
ff7f7f ff7f7f
ff7f7f
ff7fff ff7fff
ff7fff
6f0cff 6f0cff
6f0cff
ffff00 ffff00
ffff00
ffff7f ffff7f
ffff7f
ffffff ffffff
ffffff
7f0eff 7f0eff
7f0eff