For the highlight color, you will have to edit the C:\Program Files\Classic Shell\Skins\Metro.skin7 file in an elevated (administrator) instance of Resource Hacker.
The selection defining values are:
Main_new_selection
Main_new_selection_tint1
Main_new_selection_mask
Main2_new_selection
Main2_new_selection_tint1
Main2_new_selection_mask
Programs_new_selection
Programs_new_selection_tint1
Programs_new_selection_mask
Submenu_new_selection
Submenu_new_selection_tint1
Submenu_new_selection_mask
For Metro skins, the color table can be looked up using the Classic Shell Utility. Read this post:
viewtopic.php?f=17&t=4879&p=20716