Here is a great tool that I have just discovered :
http://www.biscuitsandjam.com/stripe_maker.php
It's an amazing tool to help you visualize your colour scheme as well as deciding how to go about your project if you get stuck on how to organise your colours. I love it!
The second version is weighed. It lets you decide in which proportion to use each colour:
http://www.biscuitsandjam.com/stripe_maker_wt.php
Give it a go!
