by steps
000000 000000
000000
ffffff ffffff
ffffff
00007f 00007f
00007f
0000ff 0000ff
0000ff
007f00 007f00
007f00
007f7f 007f7f
007f7f
faf7fa faf7fa
faf7fa
007fff 007fff
007fff
00ff00 00ff00
00ff00
00ff7f 00ff7f
00ff7f
f6f0f5 f6f0f5
f6f0f5
00ffff 00ffff
00ffff
7f0000 7f0000
7f0000
7f007f 7f007f
7f007f
f2e9f1 f2e9f1
f2e9f1
7f00ff 7f00ff
7f00ff
7f7f00 7f7f00
7f7f00
7f7f7f 7f7f7f
7f7f7f
eee2ec eee2ec
eee2ec
7f7fff 7f7fff
7f7fff
7fff00 7fff00
7fff00
7fff7f 7fff7f
7fff7f
7fffff 7fffff
7fffff
e9dbe7 e9dbe7
e9dbe7
ff0000 ff0000
ff0000
ff007f ff007f
ff007f
ff00ff ff00ff
ff00ff
e5d4e3 e5d4e3
e5d4e3
ff7f00 ff7f00
ff7f00
ff7f7f ff7f7f
ff7f7f
ff7fff ff7fff
ff7fff
e1cdde e1cdde
e1cdde
ffff00 ffff00
ffff00
ffff7f ffff7f
ffff7f
ddc6da ddc6da
ddc6da