Hi Shaun,
Neptune is a light blue colour, but the easiest way to confirm it is to increase the power a bit. It is around 2.2 arc-secs in diameter, so it shows as a nice circular object under moderate power (say 120-200x). It doesn't look like a star at this power (as long as the seeing is reasonable!).
If you haven't done so already, get a copy of Stellarium (
http://www.stellarium.org ) and check out the field. There is nothing near it at the moment that would be a similar colour.
Good luck, and all the best,
Dean
(PS: Only 44! Oh to have a neck that young again!