Definately doesn't look like an original colour, Ben. Can you ask the previous owner about it? What's the history on the car; rebuilt, restored, any photos of the restoration?
There's places on this side of the pond that can usually match a colour just by using a computer scan tool or such. Is there any thing like that in your neighbourhood or close by?
If you'd like some history on your car as it left the factory, the British Motor Industry Heritage Trust in Gaydon offers a certificate that will give you details such as build and shipping dates, original colour, trim, key codes, etc. You can find them here: http://archive.heritage-motor-centre.co.uk/exhibitions_heritage_certificates.html
Congrats on a good-looking car for your first. Welcome to the forum as well. Lots of good folks and great information. Where in the UK are you located? Check into local clubs as well.
Cheers
Simon