It should surprise no one that the meaning of the commentator's words was lost on you. The turning of Spencer's skin brown is not a reference to brown skin being inferior to white skin but rather a reference to Spencer's thinking that this is so. If you're racist, like Spencer, you will feel that white is better than brown/black. If you're not a racist, you won't feel that way. But since Spencer thinks white is better, nothing could be worse for him than having his skin turn brown. In fact, it might be instructional and teach him that skin color is not the difference he is making out to be, and this was the other commentator's point.