by steps
000000 000000
000000
7fffff 7fffff
7fffff
00007f 00007f
00007f
0000ff 0000ff
0000ff
007f00 007f00
007f00
007f7f 007f7f
007f7f
81fefe 81fefe
81fefe
007fff 007fff
007fff
00ff00 00ff00
00ff00
00ff7f 00ff7f
00ff7f
83fefe 83fefe
83fefe
00ffff 00ffff
00ffff
7f0000 7f0000
7f0000
7f007f 7f007f
7f007f
85fefd 85fefd
85fefd
7f00ff 7f00ff
7f00ff
7f7f00 7f7f00
7f7f00
7f7f7f 7f7f7f
7f7f7f
87fefd 87fefd
87fefd
7f7fff 7f7fff
7f7fff
7fff00 7fff00
7fff00
7fff7f 7fff7f
7fff7f
89fdfc 89fdfc
89fdfc
ff0000 ff0000
ff0000
ff007f ff007f
ff007f
ff00ff ff00ff
ff00ff
8bfdfc 8bfdfc
8bfdfc
ff7f00 ff7f00
ff7f00
ff7f7f ff7f7f
ff7f7f
ff7fff ff7fff
ff7fff
8dfdfb 8dfdfb
8dfdfb
ffff00 ffff00
ffff00
ffff7f ffff7f
ffff7f
ffffff ffffff
ffffff
8ffdfb 8ffdfb
8ffdfb