Fishbone is correct. Snakes and other reptiles don't produce urea as a waste product the way most mammals (us) do, they produce uric acid (the same substance that causes gout in humans). The benefit to this is that uric acid requires less water loss to the animal, but requires more energy to produce.
Well-hydrated snakes will secrete this as a solid form, and may excrete some liquid as well. This will all dry up rather quickly.
And yes, this is separate from their feces, although they are both evacuated from the same opening. Their feces looks like what you would expect; brown. Their 'urine' is pale yellow or white.
