
Customize the appearance of iCloud.com
On iCloud.com, you can choose a different background color for the homepage. Depending on your device’s settings, you can also use a light or dark appearance for the entire site.
Change the background color of the homepage
- Go to iCloud.com, then sign in to your Apple Account (if necessary). 
- Scroll to the bottom of the homepage, then click Customize. - Tip: If you’re on iCloud.com but not on the homepage, click  in the toolbar, then click iCloud Home Page. in the toolbar, then click iCloud Home Page.
- Click Edit Background, then choose a color. 
- Click Done in the top-left corner of the window. 
Choose a light or dark appearance

Dark Mode gives iCloud.com a dark color scheme that’s perfect for low-light environments. To use Dark Mode on iCloud.com, turn it on for the device you’re using. See any of the following:
For other ways to personalize your iCloud.com experience, see Customize and use the homepage tiles on iCloud.com.