The concept is amazing! Definitely one of the more creative ways to utilize the theme.
I got confused as to why sometimes my entire island would move to a different location, kind of destroying the point of preparing an entire tile around the surrounding. I would stay longer and paint for a bit more if it wasn't for that. The idea of claiming new colors could also be communicated a bit better - I tried to unlock them by holding it with color picker, while it seemed like I had to use a drawing tool for some weird reason.