by steps
000000 000000
000000
0000ff 0000ff
0000ff
00007f 00007f
00007f
007f00 007f00
007f00
007f7f 007f7f
007f7f
0900fe 0900fe
0900fe
007fff 007fff
007fff
00ff00 00ff00
00ff00
00ff7f 00ff7f
00ff7f
1300fd 1300fd
1300fd
00ffff 00ffff
00ffff
7f0000 7f0000
7f0000
7f007f 7f007f
7f007f
1d00fc 1d00fc
1d00fc
7f00ff 7f00ff
7f00ff
7f7f00 7f7f00
7f7f00
7f7f7f 7f7f7f
7f7f7f
2700fc 2700fc
2700fc
7f7fff 7f7fff
7f7fff
7fff00 7fff00
7fff00
7fff7f 7fff7f
7fff7f
7fffff 7fffff
7fffff
3100fb 3100fb
3100fb
ff0000 ff0000
ff0000
ff007f ff007f
ff007f
ff00ff ff00ff
ff00ff
3b00fa 3b00fa
3b00fa
ff7f00 ff7f00
ff7f00
ff7f7f ff7f7f
ff7f7f
ff7fff ff7fff
ff7fff
4500f9 4500f9
4500f9
ffff00 ffff00
ffff00
ffff7f ffff7f
ffff7f
ffffff ffffff
ffffff
4f00f9 4f00f9
4f00f9