It is not racism to want a white person to portray a white fictional character.
This competition in taking offence at any oblique reference to race specific characteristics is part of a cultural disease afflicting 21st century western society.
It is OK to want persons of specific gender/race/height or any other physical characteristic to portray fictional characters who have specific physical characteristics.
Santa Claus should be played by an old white man, preferably with a beer belly and a white beard because that is what Santa Claus is supposed to look like.