Basic Graphic Work

I have a template that I want to use on my website.. my problem is that the colors need to be changed. I have Macromedia Fireworks however when I try to change the colors on the jpg images that make up the template, it is not selecting properly and looks very ragged on the edges. I am thinking this is a job for someone who knows just a little more about how to manipulate the controls in Fireworks or Photoshop. I would like to send all of the image files (about 5) and have someone edit all of them at once. I have attached one of the images (the most difficult one in my opinion) so you can see what you'd be dealing with. I would also like to have the ability to try 3 or 4 different colors combinations if it does not look right with the colors I choose first.