Simple Graphics program?


I hope this isnt a repeat post, I searched but did not come up with anything. I am creating widgets for myself that takes the rss feeds off of websites (such as this one). I have a background that I got with permission from someone else to modify for my own usage, right now it has a purple shaded background. I would like to change that background to shaded blue. Are there any free graphics programs out there that would do this for me that any of you have used? Thanks!
Graphics Converter can do quite some things. It isn't free either, but you _might_ already have a full version on your Mac (at some time, Apple included an older version of it with new Macs...). Or use it for a while in demo mode.
The version of GraphicConverter bundled with new Macs is older for the simple reason that this wonderful app is continually updated. All the Mac user has to do is to download the OEM upgrade from Lemkesoft's website to update to the current version. GraphicConverter is such a good app that I willingly pay the shareware fee. Apple is to be commended for paying the shareware fee for new Mac owners.