Don't know about mealies and their color preferences (but if true, they certainly have good taste!), but insects do have UV photoreceptors that we lack. Flowers appear VERY different under UV light and often highlight their 'paths to pollination'. (I'm struggling to come up with some kinky human equivalent, but think maybe it's best left unsaid...)
I wouldn't discount that your plant may stand out to a mealie under light conditions it can perceive that we can't.
It's kind of cool to view your plants under UV light. I've never done it myself. (Haven't had a black light since the 60's!), but have seen it demonstrated.