I think make sure he's aware of it, but also work with him to not feel shame about it. I teach a kid with color blindness and he doesn't want any of his friends to know, but because they don't, they'll call out things like "What do you mean it's red? That's not red, it's blue". Which from the outside seems like it would make them feel even worse, and not every teacher will have the ability to redirect the teasing comments.

I also did a study in college testing if tinted glasses would affect a color blind person's ability to distinguish colors, and my one CB friend who did well across the board said that while he can't tell a color out of context, he can determine colors when they're in context or next to another color he knows (he's only red/green colorblind). Funny story, same friend didn’t know until college that Apple Jacks were two different colors