Apple mail turn on colour conversations cannot turn off

A frustrating issue!

It sounds like you're experiencing a problem with Apple Mail where the "Color Conversations" feature won't turn off. Here are a few potential solutions to help you resolve this issue:

  1. Check the Mail preferences: Open Apple Mail, go to Mail > Preferences, and click on the "General" tab. Look for the "Color Conversations" option and make sure it's unchecked. If it's already unchecked, try checking it and then unchecking it again to see if that resolves the issue.
  2. Reset Apple Mail: Sometimes, resetting Apple Mail can resolve issues like this. To do this, go to Mail > Preferences, click on the "Accounts" tab, select your email account, and click the "Reset" button. Then, restart Apple Mail and see if the issue persists.
  3. Check for updates: Ensure that you're running the latest version of macOS and Apple Mail. Sometimes, updates can resolve issues like this. Go to System Preferences > Software Update to check for updates.
  4. Try a different email account: If the issue persists, try creating a new email account in Apple Mail and see if the problem occurs with that account as well. If it doesn't, it could indicate a problem with your original account.
  5. Reset NLS (Natural Language System): This might sound like a weird solution, but resetting NLS can sometimes resolve issues with Apple Mail. To do this, go to Terminal (in Applications/Utilities) and type the following command: defaults write com.apple.mail NLSReset -bool true. Then, restart Apple Mail and see if the issue persists.
  6. Reinstall Apple Mail: As a last resort, you can try reinstalling Apple Mail. Go to Applications > Utilities > Disk Utility, select your startup disk, and click the "Erase" button. Then, reinstall Apple Mail from the App Store.

If none of these solutions work, you may want to consider reaching out to Apple Support for further assistance.