The Light mode is designed to work well during daylight hours. If you choose this option, you’ll be able to show an accent color for window title bars and borders .
The Custom mode gives you options between Light and Dark. You can choose an accent color, or have Windows select one (the accent color will provide a contrast with, or match, your wallpaper and Windows color). This option is for the Start menu, taskbar, and action center. You can also show an accent color for window title bars (the horizontal bar at the top of a window) and borders. You can play around with the colors and modes to see which ones work best for you.
