As part of the new Theme customizer, we'd like to introduce a new way to customize the Footer color:

• 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 [here|https://jira.greenpeace.org/browse/PLANET-5552) and Footer (described in this ticket)
• the Footer section would have two radio button options: Light, Dark
• 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 Footer color, the Footer text and link colors and the Footer icon colors (Dark footer color will switch to light color for text, link, icon colors and vice versa)
• Every theme would have a default value specified by the design team, the respective radio button would be pre-selected