What colour is the wind?
Blew!
Nirvana is a Sanskrit word compounded of nir-, 'out', + va, 'blow' + na, which makes a noun of a verb. So the literal meaning is something like 'outblowing' but as used in a number of religions it refers to a state in which the soul is liberated from the endless cycle of death and rebirth and the passions that are responsible for our suffering are extinguished, 'blown out'.
Now the va element derives from a Proto-Indo-European root *we-, 'blow' and that is also where wind comes from. So the word wind tells you what it does - it blows.
Other cognates include Old Norse vindauga, 'wind-eye', which was borrowed into English and has become - can you guess what? There is also Latin ventus, 'wind', and Ancient Greek (atmos). You'll see what modern word is descended from this, but if this is cognate with wind, where has the 'w' (or 'v') gone?
Well I'm guessing here, but Ancient Greek dropped its 'w's. Even-more-Ancient Greek had a character that was pronounced as 'w' but by Classical Greek times this had been lost. We can see other examples of this in Greek oenos, 'wine', and ergos, 'work'. So my theory is that it was originally watmos, which ties in a lot better.
Today, in English at least, Nirvana has acquired a secular meaning of a sought-after place of perfect contentment, or simply a special paradise, and so we have coinages such as Beervana, a real-ale enthusiast's ideal place, and Nerdvana, somewhere or something that is a paradise for nerds.