On Start , swipe over to the All apps list, and then select Settings > Personalization . There you can choose a picture worthy of gracing your Start screen and change your background and accent color. The preview window gives you a sneak peek of your changes as you make them.
In Start, select a picture or use your accent color as the background. You can also tinker with the number of tiles, or change the transparency of all the tiles for a better view of a fullscreen picture in the background.
In Colors, select light or dark mode, and pick an accent color.