Why is it that colloquial names for races are endlessly deemed derogatory

(I heard recently that 'oriental' has ceased to become acceptable in America - North Americans may find it impossible to NOT conceive of it being derogatory; I daresay that many Brits may be surprised by the development)

yet "white" is still used openly and without question.

I'm thinking that maybe people are derogatory about a specific race, and so the name used is considered derogatory, because it has been used in a derogatory way.

But these names, as in all generalisations, are more UNSPECIFIC than derogatory.

"White" is not specifically accurate. But it would only become derogatory if used consistently so, in a dominating and frightening manner.

"Here comes whitey..." ringing out on every corner of the streets.

The names can't encompass every aspect of every member, they will keep changing and the attitudes wont change.