Appropriate use of color makes your screens more glanceable. Use colors effectively considering the watch and its system's characteristics as a wearable device.
Use dark-colored themes
App screens should be visible both under direct sunlight and in lower light settings. Use dark colors for the background to enhance content readability without disturbing people with too much light. Dark-colored themes also consume less battery power and blur the boundary between the bezel and the screen.
Use a strong contrast
Information should be easily visible to users on the watch's small screen. A strong color contrast distinguishes text and icons from the background.
Use consistent colors
Users should be able to recognize your app. You can design your own theme, and apply it to your app to differentiate it from others. Use consistent color swatches to enhance visual communication with users.
The following example shows how default theme colors are applied if the watch’s default system theme color is set to dark blue.