Open Microsoft Word
Click File
Click Account or Office Account
Under Office Theme, select White or Colorful
Close and reopen Word if needed
On Windows, you can also go to File
Click Options
Click General
Under Personalize your copy of Microsoft Office, choose White or Colorful
Click OK
On Mac, open Word
Click Word in the menu bar
Click Preferences
Click General
Set the Office theme to Light or White
Close Preferences