Hey Hairy Shark, I've discovered a program called: "FastStone", it lets you play with all the colours, so far its free......
I use FastStone myself and I found very easy to use after a short learning curve. Once you're accustomed to it you can work wonders with your editing. It's free for private use but if you want to use it for business, there's a license fee to pay, but you really don't need to go that far. The free software has many if not all the features you'll ever need. I use FastStone for my business. Go or it! There's also a tutorial for it as well.