AeroTuner is a simple, portable tool for customising the look of Aero on Windows 7 PCs.
The program allows you to choose separate main and glow colours, for instance, and enable (or disable) transparency at a click.
Sliders then make it easy to tweak your colour balance, after glow colour balance, blur balance and aero stripes.
And if you've no idea what these might do, that doesn't matter at all: just tweak them as you like, and the program will immediately update the screen so you can see the results. If you've made things worse, just close AeroTuner or click "Restore" to restore the default settings. Or, if you're happy with the new look, click Save to make it permanent.