Family Connections

Hi,

I am researching my family tree at the moment and would like to ask a couple of questions.

We believe Mr A is the father of Mrs B with a child Mr C. We know that Mr A had a son with another woman Mrs M, lets call the son Mr X, whol also had a son Mr Y. This would make Mr C and Mr Y half cousins. Is there any way of establishing a family connection using DNA testing?

Mrs B and Mr C have black hair and light brown eyes. Mr C is 5'9 and Mrs B is 5'0. Their skin pigmentation is also mediterranean looking. We believed they were of Italian ancestors. However Mr A we know at 50+ had brown hair, brown eyes but white skin and apparently didn't look Italian (and didn't have any features of Mr C according to one woman who knew Mr A). Having done some research I found Mr A was half German, from Bavaria (on his mother's side) - funnily enough a Bavarian I work with looks like Mr C (dark hair, light brown eyes and tanned skin). Is there any way that Mr A's mothers genes were passed to Mr A in an inactive state, and then were passed to Mrs B in an active state? I also read that skin pigmentation can be affected by the environment - Mrs B did sunbathe a lot, perhaps Mr A didn't and his skin pigmentation changed over time.