It seems to be a bug with colors when copying with code one object color to another.
Also when setting RGB values directly through code, I get the same issue, as if iOS interprets the values differently.
While on the PC everything looks ok, when running the app on iOS the colors are completely wrong.
I encountered the issue so far with string objects and with text of active system box. Haven't tried other objects, but it might be present as well.
(I'm using iOS version 6.1.3, and latest beta of MMF developer).