Another recoloring technique...

[A.J. Nitro]

Weird. I never knew about making the eraser big. I'll I've been doing was selecting the whole sheet and making the unwanted color transparent, then coloring that to what I want. But what I've been wondering is when you hold down the Ctrl key and choose a color, that big white square at the bottom left of the screen changes to that color. What does that do?