Depends on the edition and/or setting.
I'd suggest there was an underlying assumption that all races are pale-skinned, because looking through some 2E material (PHB, Complete Book of Elves), it's only when a race is not pale-skinned that it's specified. For example, in the PHB, no racial skin tones are specified except the "dark tan" skin of Gnomes, and the "ruddy cheeks" of Dwarves (weird flex but okay). In the CBoE, Drow are specified to have dark skin (in the "full racist" creation story it offers as), but High Elves, whilst their eyes and hair are specified, their skin is not, for example.
But you could read this either way - either it's mildly subversive, and even in 2E, the writers wanted to allow us to have dark-skinned hobbitses or whatever, or they're just assuming everyone is white and not even thinking about it. I tend to think the latter, but...