
I agree with DawnBringer. You can probably use even larger tiles than I did, and then you'd have room to add patterns/flowers to some of them like some older bathrooms. I can't find an example of one of those though.
I also think that the dark tiles contrast too much.
The lightest tiles blend in with the seams (my edit isn't doing a good job at fixing that though, I don't know what colour would be appropriate).
I'd also suggest using something other than blue for the bulk of the background. Now the background and the character have similar colours. The pink one didn't look much like a bathroom, but it did make the characters stand out.