If you are app is on version 6.0.0 or higher then the following settings will change the colors in your Web app, Android app, and iOS app.
Primary Text Color- This controls the main text throughout the app such as: Titles, Bold Text, etc.
Secondary Text Color- This controls any subscript text, description text, etc.
Primary Background Color- This controls any foreground background colors and will be the most prominent background color.
Secondary Background Color- Anywhere the primary background color is not shown, the secondary background color will be behind it. It is recommended to be a slightly darker shade of the primary background color.
Theme Color- This will be the most dominant color throughout the app and is used anywhere that needs a color and doesn't fall into the above categories.