Right off the bat I'm a newbie with Photoshop. But upon messing with it and learning from tuts on you tube. One of things I love using the program for is changing car paint jobs on a photos to see what the vehicle I will be painting will look like upon completion, before I start the actual job. Now like I said I'm a newbie so this may already be a feature in the program and I just don't know how to use it yet. But I noticed that in order to change a color you have to first select the area you want to make the change to. I have a pic that I'm working on where I wish I didn't have to select the area, but instead be able to target spectrum specific colors and change them via the hue option. For example: I want to change a green to red. I would love there to be an option where i didn't have to specify the area i wanted, but just be able to change the entire image of greens to reds without affecting the other colors, and when I say greens to reds, I mean greens including the related spectrum color of the greens, the light and dark greens that may also be in the picture would turn into light or dark reds respectively following the shades the green had.