You're looking for information on Nokia's Light and Nth themes!
usually employed:
"10 Beautiful Nokia Lumia Themes to Brighten Up Your Day: Focus on Light Theme" nokia light.nth themes
A music-centric phone where themes often matched the side-panel colors. You're looking for information on Nokia's Light and
: It uses internal XML configuration files to define layout settings, color schemes for menus, and font styles for user interface text. color schemes for menus