This page of dotCover options allows you to choose the keyboard shortcuts scheme.
You can switch between three color schemes for Visualizing Code Coverage.
If necessary, you can configure each color individually in Visual Studio options:
Choose Tools | Options | Environment | Fonts and Colors, and then find entries beginning with 'dotCover'.
dotCover's settings are saved in settings layers that enable you to have different settings for different solutions as well as to share your settings with your team. To learn more, study the Managing and Sharing Options section.