This video will explain to you how to change the desktop background and Start Screen Color.you can change Desktop Background
Click on windows start button
Start
then select Settings
Personalization
In Background, select a picture or solid color or create a slideshow of pictures.
from Personalization you can change colors: In Colors, let Windows pull an accent color from your background, or choose your own color adventure.
After you've selected an accent color, scroll down to decide where you want to see the color show up, and whether it looks better in a dark or light setting.