I had something similar when I shot the great pyramid in midday sun with my 5D. I think it is just some channels clipping before others, i.e. insufficient data to get the colour right.
Posted this in the B&W section, but this is one of the first shots I've taken with my 135/2 ZF.2, so I thought I'd post it here too.
I'm really digging it. looking forward to trying some astrophotography with it next new moon (as long as the cloud cover cooperates, which we all know it won't since that's how things like this go..heh)