Delete the background layer, then add a group folder at the top of the layer stack. Shift + click your top and bottom layers and drag them into the group folder. Cmd/Ctrl + click on your new Channel thumbnail to generate a selection. Target the group folder and go Layer > Layer Mask > Hide Selection to trim away the excess areas. Target the ‘Mouse top outer’ layer and draw closed paths around the areas circled in red, make a selection and hit Delete.
Disable the visibility of all layers but ‘Mouse back outer’ and clip an adjustment layer by holding Alt/Opt while clicking on the ‘Create new fill of adjustment layer’ icon at the foot of the Layers palette. Select Hue/Saturation. In the next dialog box check Use Previous Layer to Create Clipping Mask. Set the Hue to 171 and the Saturation to 25 with the Colorize preset checked.
Set the ‘Mouse back inner’ layer’s blending mode to Pin Light; clip a Hue/Saturation adjustment layer, setting the Hue to 296 and the Saturation to 25 with the Colorize preset checked. Do the same for the ‘Ball’ layer using Hue = 318, Saturation = 31, but leaving the blending mode unchanged.