Welcome to the Seven Forums
1st
You need to use a copy of the aero theme to make a custom theme so you do not damage the default theme.
Look at post #38 it will show you how to start a new theme
Start menu color change ??
2nd
This will be a custom theme and you will need to do 1 of these 2 ways of Enabling custom themes for it to work.
Enabling Custom Themes - Windows 7
Or
Theme - How to Apply Custom Themes
3rd
Open the new themes .msstyles up in Windows Style Builder
4th
Here is a start after you get this will help more.
Look at screenshots

1
Explorer & Shell > Explorer > CommandModule > <1> (edit the
image)
2
Explorer & Shell > Explorer > PreviewPane > <1> > <1> (edit
the image)
3
Explorer & Shell > Explorer > Menu Bar > Background (edit
the image)
and
Toolbars, Headers and Rebar > Rebar > Rebar (edit the
image)
they need to be to same
4
Explorer & Shell > Explorer > Items View > ItemsView >
FILLCOLOR:COLOR (change the color)
5
Explorer & Shell > Explorer > ProperTree > <2> >
FILLCOLOR:COLOR (change the color)
The 1st time you go to edit a image it will ask what image editor you want to use navigate to your editor .exe in the program file.

If you need more help let me know
Jerry