by steps
000000 000000
000000
806080 806080
806080
00007f 00007f
00007f
0000ff 0000ff
0000ff
007f00 007f00
007f00
007f7f 007f7f
007f7f
805f7f 805f7f
805f7f
007fff 007fff
007fff
00ff00 00ff00
00ff00
00ff7f 00ff7f
00ff7f
815f7f 815f7f
815f7f
00ffff 00ffff
00ffff
7f0000 7f0000
7f0000
7f007f 7f007f
7f007f
815f7e 815f7e
815f7e
7f00ff 7f00ff
7f00ff
7f7f00 7f7f00
7f7f00
7f7f7f 7f7f7f
7f7f7f
825f7e 825f7e
825f7e
7f7fff 7f7fff
7f7fff
7fff00 7fff00
7fff00
7fff7f 7fff7f
7fff7f
7fffff 7fffff
7fffff
835e7d 835e7d
835e7d
ff0000 ff0000
ff0000
ff007f ff007f
ff007f
ff00ff ff00ff
ff00ff
ff7f00 ff7f00
ff7f00
ff7f7f ff7f7f
ff7f7f
ff7fff ff7fff
ff7fff
845e7c 845e7c
845e7c
ffff00 ffff00
ffff00
ffff7f ffff7f
ffff7f
ffffff ffffff
ffffff
855e7c 855e7c
855e7c