Jesus is an idea as well as being, to some people a historical character. As a historical character (if non believers like me suspend disbelief for a moment, we have no real idea what he looked like but it's fairly certain his looks would be more like modern Greeks, Turks or Arabs (i.e. Indo - caucasian) rather than sub saharan African.
If we take the view that Jesus aka The Messiah is an idea, then there should be no reason why human respresentations of that idea cannot fit the culture of the intended audience, European, African, middle eastern, Asian or oriental.
It is notable that the people wanting white Jesus banned are are supporters of radical left wing politics so presumably they want to standardise on Red Jesus carrying a red flag instead of a cross and wearing a Che Guevara T shirt..