by steps
000000 000000
000000
0000ff 0000ff
0000ff
00007f 00007f
00007f
007f00 007f00
007f00
007f7f 007f7f
007f7f
0801f8 0801f8
0801f8
007fff 007fff
007fff
00ff00 00ff00
00ff00
00ff7f 00ff7f
00ff7f
1003f1 1003f1
1003f1
00ffff 00ffff
00ffff
7f0000 7f0000
7f0000
7f007f 7f007f
7f007f
1805ea 1805ea
1805ea
7f00ff 7f00ff
7f00ff
7f7f00 7f7f00
7f7f00
7f7f7f 7f7f7f
7f7f7f
2007e3 2007e3
2007e3
7f7fff 7f7fff
7f7fff
7fff00 7fff00
7fff00
7fff7f 7fff7f
7fff7f
7fffff 7fffff
7fffff
2808dc 2808dc
2808dc
ff0000 ff0000
ff0000
ff007f ff007f
ff007f
ff00ff ff00ff
ff00ff
300ad5 300ad5
300ad5
ff7f00 ff7f00
ff7f00
ff7f7f ff7f7f
ff7f7f
ff7fff ff7fff
ff7fff
380cce 380cce
380cce
ffff00 ffff00
ffff00
ffff7f ffff7f
ffff7f
ffffff ffffff
ffffff
410ec7 410ec7
410ec7