by steps
000000 000000
000000
ffffff ffffff
ffffff
00007f 00007f
00007f
0000ff 0000ff
0000ff
007f00 007f00
007f00
007f7f 007f7f
007f7f
f1fefd f1fefd
f1fefd
007fff 007fff
007fff
00ff00 00ff00
00ff00
00ff7f 00ff7f
00ff7f
e3fdfc e3fdfc
e3fdfc
00ffff 00ffff
00ffff
7f0000 7f0000
7f0000
7f007f 7f007f
7f007f
d5fcfa d5fcfa
d5fcfa
7f00ff 7f00ff
7f00ff
7f7f00 7f7f00
7f7f00
7f7f7f 7f7f7f
7f7f7f
c7fbf9 c7fbf9
c7fbf9
7f7fff 7f7fff
7f7fff
7fff00 7fff00
7fff00
7fff7f 7fff7f
7fff7f
7fffff 7fffff
7fffff
b9faf8 b9faf8
b9faf8
ff0000 ff0000
ff0000
ff007f ff007f
ff007f
ff00ff ff00ff
ff00ff
abf9f6 abf9f6
abf9f6
ff7f00 ff7f00
ff7f00
ff7f7f ff7f7f
ff7f7f
ff7fff ff7fff
ff7fff
9df8f5 9df8f5
9df8f5
ffff00 ffff00
ffff00
ffff7f ffff7f
ffff7f
8ff7f4 8ff7f4
8ff7f4