Help needed building a colour thing!

HI
Can anyone help me here? I'm trying to make a colour choice thing?? What I
need is a page that shows a tent (the kind you sleep in outside), I have a
colour chart with approx. 10 colours for the tent and another 10 or so for
the flysheet(the bit that protects the tent).
What I'd like to do is for the user to click on the flysheet and then a
colour and the main picture to change to show this colour, the same with the
main tent. This way they can mix and match any colour tent with any colour
sheet.
Can anyone help me with an easy way to set this up, maybe using some
software to make it realy easy, I've written a few sites, if you look at
'tyleruk.com', then you'll see my level of expertise is not that good.
Any questions or suggestions will be appreciated.

Thanks in advance
Si