This brush is single use and can only be used to color one dino.

How to use:
Equip the brush and hit the dino you want to color.
You can select the colors using the GUI.
You can see all the colors without applying.
When you are happy with your design, simply click 'Apply colors' and it's done.

When activating the brush by hitting your dino, you only have a certain amount of time (more than enough). If you take too long, the brush is destroyed. You can move around the dino, but if you go too far away from it the brush is destroyed.
For both of these there are clear alerts and a countdown, to indicate what is going on.