Snowball is not offenSive to white people as it does not have the underlying connotations that certain words used to describe black people in a negative way have.
I used to drink in an illegal bar run by, and populated entirely by, members of Sheffield's Afro-Caribbean community. I was the only white guy allowed in and I was always referred to as 'da white ***'. I regarded it as a compliment!
Some time ago I bought a book of non-pc jokes. In the forward the author made the point that "If someone hits you on the nose it hurts, no argument. If someone calls you a name aiming to offend you, you can CHOOSE whether or not to be offended; just choose not to". It works wonderfully well if you just ignore them and even better if you agree with them - their insult has failed and you have got one up on them. Try it.
''Sticks and stones will hurt my bones but calling names won't hurt me''
This is what we used to chant when we were kids whenever the other kids were taunting us.
And no ,the name Snowball is not offensive to our family. My niece married a lad with that surname.