Ten degrees?!?!?! BRRRRRRRR! Stay warm.
You can achieve the selective color technique you asked about in Photoshop Elements. You can buy the latest version (8) for around $85, or you can find an older version for less than $50. It will do 90% of what most photographers need. There are other software packages, but because Photoshop is the industry standard, it tends to have more sources of assistance (forums, blogs, websites, turorials, books, videos, etc.) than any other.
Another popular package is Paint Shop Pro. I haven't used it, but people who have rave about it and say that it can pretty much do everything that Photoshop does for a fraction of the price. I just did a quick search, and there appear to be a few different versions. I don't know what the differences are, but I see
Amazon has the "X2 Ultimate" version for just $25. Not to disuade you from purchasing this product, but 99% of the photo editing explanations you find on the web use Photoshop terms and tools, so you may be on your own and have to do some digging to discover how to apply them to the Paint Shop Pro world.
Free options include Picasa and GIMP. Again, I haven't used either of these, but Picasa manages your photo collection, simplifies the process of uploading the images to the Picasa photo sharing site, and it includes some fundamental photo editing tools. GIMP is supposed to be a really powerful free alternative and worth exploring.
Good luck!