As part of the new Theme customizer, we'd like to introduce a new way to customize the Navigation bar colors:

• We'd like to add a new section under Themes called "Color Settings"
• Under this section there would be two sub-sections, Navigation bar (described in this ticket) and Footer (described in a follow-up ticket)
• the Navigation bar section would have three radio button options: Light, Dark and Transparent
• Every theme would have two values specified by the design team (for Light and Dark), the radio buttons would switch between these values. This radio button would control the Nav bar color and the Greenpeace logo color (dark logo on light navbar and vice versa)
• Every theme would have a default value specified by the design team, the respective radio button would be pre-selected
• There would be a transparent color option too - Design team needs to specify the logo color in this case