Just fyi, this is solely my opinion and I don't mean to offend in any way, just want to offer another perspective.
I tried this on the other day as I am a lover of rainbow colors. And I wanted to love it, but it felt kind of tacky to me, I think there is too much going on for a Chanel bag, plus I don't like the little pendants/thingies in the chain.
But I also have changed my style a bit and a few years ago, I surely would have bought it.
I don't really see it as an evening bag. There are really cute alternatives every season for evening bags and you already have a few. Plus it would really limit the times you would wear it.
But you obv love it, so you have to do what your heart desires.

Wishing you all the best.