Story Related: Unmissable.
You need to Paint 2 Rocks gold and place them in a box.
Open the nearby door and place a force beam between the wooden door and nearby wood and shoot through the beam, hitting the button on the nearby supra ball dispenser.
There might be a fancy way to get around the anti supraball field, but I just shot the ball over it to land on the small island with the color changer and then shot the ball into the color changer. It's safe to use full power when shooting into the color changer, don't do a soft shoot and drop the ball into the lava instead like I did :P
Place rocks onto the color changer and then Shoot at the button through the Anti Supraball field to activate it.