I think the colors match but the gain and the contrast are off as there is a sudden jump in detail. Particularly at the low end So the Values are off between the 2. That should be pretty easy though.
Although I think it might be a bit too slow now you should perhaps go to 90% Speed but also slow the original clip down to 90% also so the speed of the rain does not change.
But I am really impressed that you pulled that off. I think it’s great work. Hat’s off. I actually need to do something similar myself at some point did you use an image sequence for this?
Anyway this is what I think. In fact if you did it like this it would be a cut overall. But it would still be an improvement. Sometimes less is more.