If you like you can change some specific colors within WBConfig (what you open to change skins).
Copy off your skin directory first to back it up, changing these colors actually changes the skin. Also changing these colors changes them for anything that uses these colors, not just a particular app. Best to make subtle changes to try to keep everything looking decent.
click on "Colours" tab on the bottom
click on "Change skin system colours" button in the lower right corner
These are notes I've taken which should get you started, some color assignments may vary based on o/s and app version:
Excel tabs- SystemColour: ButtonFace
Excel tab text and statusbar text- SystemColour: Button text
Excel general window background color- SystemColour: Window
Excel general window text color- SystemColour: WindowText
Dropdown backgrounds: SystemColour: Window
Dropdown text: SystemColour: WindowText
Adobe Photoshop Elements Status Bar- SystemColour: ButtonText
Adobe Photoshop Elements Status Bar Text - never have found that one despite my best efforts
Adobe Photoshop Elements general window background- SystemColour: AppWorkspace
Once you get the skin looking the way you want it you'll want to copy off the skin directory again to backup your changes.