Can "Kim" be considered as a racial text?
Absolutely. In fact, from a contemporary point of view, it is impossible to dodge the racial implications of the book. Kipling may have intended this as entertainment, and as political. However, while Kim's heritage may have been pure, the fact that he passes for members of different elements of society makes him a useful metaphor for how racial definitions shift and blur. "Kim" shows race as a construct.
Some also see "Kim" as a racist text, due to descriptions of character, like this one: "His face was yellow and wrinkled, like that of Fook Shing, the Chinese bootmaker in the bazar. His eyes turned up at the corners and looked like little slits of onyx."
Race is clearly a major theme, but racism (hostility or hate toward a particular race) is another thing. I haven't finished the book yet, but I am struck by Kipling's love and fascination for many races, cultures and religions as expressed by his character, Kim. He uses Kim's naive and shamelessly accurate eye to poke, prod, stroke, mock and blast every social group, even (or especially) sub-groups within a particular race. But he highlights and defends the strengths he sees in every group with the same clarity.