Color help!😪

I wanted to do a mermaid theme for our nursery. I've already painted the room blue, and I was going to do an accent wall of fish scales. I did one small part the other day (it took FOREVER) and I don't really like how it came out. I think it may be too many colors for such a small space and room. Here's a picture, the second one shows how small it looks on the wall

Do you think it would look better if I did the whole wall in that light green color with maybe a few pink ones scattered in? Or should I give up and just look for something else 😫😟