Switching Dark mode fails on loaded messages

[the-djmaze]

Describe the bug
When turning on 'Remove background and text colors from message body', it does not remove the colors from already loaded/read messages.
When turning off, it does not add the colors back to already loaded/read messages.

To Reproduce

1. Go to 'Settings'
2. Click on 'Remove background and text colors from message body'
3. Go to mailbox
4. Read already loaded message

Expected behavior
Remove colors from already loaded message.

Workaround
Reload browser window (F5)