1 problem – ASMR Coloring! Review

I luv this game but there is 1 problem. When u tap a pixel that u already colored, it changes that pixel to that color and u have to recolor it. Let's say ur coloring a cat. If u tap a colored pixel it will change on the cat. Also, the color can go through the cat and color the other side and change the color of a colored pixel. PLZ FIX THIS
Review by Unicorn Unikitty on ASMR Coloring!.