Start by opening image in camera raw, this way you can open it as a smart object in photoshop. This is what makes it to where you can adjust the color of the other layers within camera raw. After the original is opened as a smart object make a new smart object via via copy. Creating a copy in this manner gives you the ability to change the processing on this layer and not affect the other layers.
step 2 of 5
Double click on the thumbnail of the copy that you just created and that will take you into camera raw once again so you can make adjustments changing colors on just this layer. Once done with the processing in camera raw, click ok and changes will be updated and you are returned to photoshop. Repeat previous steps including creating new smart object via copy for each color adjustment
step 3 of 5
step 2 continued
step 4 of 5
Step3
step 5 of 5
I saved mine in layers as well as a jpg copy, that way I could make changes if I want to later.