I've used a June Talor mat for lots of cutting and am quite happy with it. They are much tougher and harder than most, the big one I have is great for cutting strips or other long straight lines but I wouldn't recommend them for cutting a lot of curves as their harder surface would wear out blades fast.
Here's an idea: darken your cutting mat with a permanent. I'd suggest colloring an inch or so of one corner in a dark color, let it dry for a couple days, then try cutting on it and rub fabric on it to see if the ink transfers, also turn it over and rub it on your work table to check for ink transfer. If it all comes away clean color the rest of the board. If not, just sandpaper it off and move to the next solution.
Did you know that flexable cutting boards are basically thinner cutting mats? You could get a pack of brightly colored ones at the store and use them until you can afford a sturdier mat.