Reusable countdown animation

The ability to have a full-sized transparent countdown that I could paste over any background. Ideally, maybe one white, one black, and one beige countdown that could overlay over any background (depending on my background's color) and provide a solid, good-sized countdown. I imagine (possibly erroneously) that this would not be difficult to accomplish. It may not be feasible at this time, but y'all never know what folks want if we never mention it.