Yes, they can have spots of different-coloured skin under their fur. It’s normal as long as it is just smooth skin, no crustiness, bleeding, scabbing, dandruff-like skin flakes etc.

Yes like bam said, its like what dogs have on their skin, like a dog can be white or black all over and have a red or brown mark, we have them too sometimes, people can be white skinned and have dark patches, dark skinned people can have different colour patches too, its all normal like bam said unless there is little sores etc, but a tiny sore to us is big for a bunny.