Depends on the brand, but usually they're colored blue or white for colder and red or yellow for warmer. Cold waxes are also firmer than warm waxes, might be able to tell the difference by feeling them. Other than that, no way to really tell without know where they're from.
Check out skifastwax.com for an idea of what to expect, or just grab some new wax from em cause their wax is sick.
Set the iron to the lowest setting and see how it melts, that should give you an idea of where it is. I get HF Swix wax in bulk with out the containers, so its good to start wrapping them and marking them. For most applications I would think what ever it is would be fine for your needs. unless you are racing.