oke .. now its clear.. the subpixels RGB can be turned off or on in low powermode only.. so there are only 8 colors available

000000
ff0000
00ff00
0000ff
00ffff
ff00ff
ffff00
ffffff

the only thing i noticed is that only ffffff grants a smooth font face.. all the others look a little bit odd (maybe because the pixels that are lit are too little and to far away from each other)