Why did my nail color turned into this "yellow" color?

So, I'm pretty new to painting nails, and this is the second time I painted them ever.

I painted my nails 5 days ago and applied a top coat. I applied a second layer + top coat 4 days ago, since I managed to scratch the paint quite fast. The second layer only covered up the scratches. Today I realised, that the paint started to get this yellowish tone. Primarily around the areas where I applied a second layer.

Is there something I could have done to prevent this?

Edit: the different colors are all fromthe same brand (the top coat is from a different brand) and they all have this phenomenon).