How do you change the colour of your skin?

Click on your character's icon at the top left of the screen. Then click on the tab at bottom of the screen labeled: family. Once here, select your character and click on the button called: Editor.

Editing to the skin can be done on the second side tab (the button with the mask).

When you first start the game you'll only have two skin options. You earn more by finding them in treasure chests which are bought with the coins you earn in game by battling other animals. Each treasure chest cost 1,000 coins to open (which doesn't take too long to earn).