Yes, COLOGNE is a Scrabble word!

Letter values in Scrabble US: C 3, O 1, L 1, O 1, G 2, N 1, E 1.

Is it a valid word?

COLOGNE is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a commercial center and river port in western Germany on the Rhine River; flourished during the 15th century as a member of the Hanseatic League
a perfumed liquid made of essential oils and alcohol

Also: cologne water, eau de cologne.

Not playable in Scrabble US: KOLN.