I have debug visualizations for various bits of data in my game such as collision info, object origins, target vectors, etc.
When I have many of these active at once (like when when working on AI behaviors) it can be tricky to see the difference between them when they're all rendered in the same color.
(I realize this particular screenshot isn't like super difficult to parse but it's an example of the different types of visualization I use. When I add in tile collisions and targeting vectors its a lot.)
I would love to be able to specify different colors when doing debug drawing so I can have collision rects all one color, sensors another, AI info another, and so on.