Its actually colors of the sun but let insecure brehs like you tell it.The blond hair and blue eyes are undeniable cac like traits in Dbz but besides that in general people give cacs waaaaay too much credit in thinking everyone looks like them in manga/anime. Certain series certainly do a service to make sure characters look like cacs (ex. Attack on Titan). Most manga/anime characters look vastly different, first off if they wanted it accurate gotta start off with the redskin.
yellow red and blue are all colors of the sun...