hi,
could you help me to the somewhat similar issue, I am able to give permission to style definition but after doing that in mashup properties under style it says "not found" and because of that I am not able to apply any kind of styles on mashups, my concern is have you faced this issue as well.
note : i guess this is the reason why you are also not able to get the background colors, because of style definitions.
Regards,
Abhishek Kumar
