Selecting favourite ethnicities is promoting Racism.
Not really, it's just that too many people in the developed world are too scared to even accept that even the smallest difference exists between "races" (which is a silly and innacurate term TBH).
Saying you're atractred more to white girls over black girls/boys is no more racist than saying that you like tall girls/boys over short ones, or that you like X hair color and so on.
It's just a prefference, everyone has them.