Use the Arrow Keys to move and jump. When you are standing in a color-pool, press D to add more of that color to the background, or A to remove it. You can make any obstacle disappear by matching its color with the background!
In later levels you will find paint buckets. Press W to set your paint bucket to the same color as the background. Then later you can press S to use the paint and turn the background into the color you stored up.
Mix and match colors to make your escape!