That's funny that he doesn't like red bell peppers because paprika is made of red bell peppers and chili peppers.But so far he does not seem to like the red veggies I give him (carrots, yams and red bell pepper), especially the red bell peppers.
Maybe you can dry a pepper, dehydrate maybe, and then grind it up to sprinkle over his food like you did the paprika? Just a thought