When dealing with colors, make sure you are using a proper monitoring setup (broadcast monito and IO card). If you can't see it, you can't fix it.
Next, check if the file was saved as sRGB1966 in Photoshop. It's one of the oldest but most widely compatible color spaces. Also make sure you interpret the gamma level properly in FCP. To do that, select the clip either in the timeline or in the browser and hit apple 9 for item properties. Go to gamma and switch source to either 2.2 or 1.8. (can't remember which one, also it depends on how you created those images).
www.strypesinpost.com