You do know that the black on the face of the disc, where the pads contact, will get worn off the first time you use them?
It'll only be left in the centre and on the outer rim - and I can't imagine that'll last too long because of the heat.
Personally, can't see that they'd look much different to standard discs - the bits that aren't constantly worn by the pads would just end up covered in brake dust anyway.
But I could be wrong.