I took some photos of my niece and I am trying to change the pink bow in this photo to match the ruby colored slippers. I have photoshop elements 7 and lightroom 3. I am a novice when it comes to either of these programs and have learned by a lot of experimentation and the help of Scott Kelby's books, but this time I just can't seem to get it right. If any of you out there could point me in the right direction, I would truly appreciate it!
When I need to change colours without losing the detail, I use a method similar to @christiq - I first use the eyedropper tool (with brush selected, alt-click the shoe to get a matching red), then create a new layer, change blend mode to "color", and using the brush paint in over the bow. If you make a mistake, you can just erase it back or ctrl-z. I am working on the assumption that Elements 7 has the "color" blend mode option. For an example of what I'm talking about, see where I corrected hair colour in this tutorial on blend modes: http://365project.org/discuss/tips-n-tricks/7058/how-to-photoshop-blend-modes