Add variations of themes with colored menu bar

Current Situation

• A number of themes are available, however, they address different usage scenarios, e.g. for users with disabilities themes with higher contrast have been added.
• At the same time users would like to use the same theme with minor changes to reflect use with production and non-production environments.

Desired Behavior

• A theme variation is derived from a basic theme, e.g. the "Light" theme. A number of variations of this theme should be available with differently colored menu bars (currently in dark blue), i.e. a blue, red, green etc. menu bar.
• For future development modifications to a basic theme should be easily applicable to all variations of the theme.
• Some 10 theme variations based on the "Light" theme should initially be available.