Your 'red felt' is a 100 times better then my horrid attempt to paint up some plastic overhead projector sheet. I tried a mixture of red orange and yellow paint and, well, the result was horrendous. Thankfully there is no photographic evidence.
Also, thankfully (and a little sadly), the lava was not required. In the scenario the lava shows up in turn 4, and our game did not make it past turn 3 before a victor was crowned!