There must be sufficient contrast between the text/images and the background - min. 4.5:1
Users can understand everything without relying on color
For important user actions, the user should be given an opportunity to undo anything they didn’t mean to do
The user’s “context” should be constant after changing a setting or entering information
If an error is detected in a user’s input, the error should be identified and described to the user in text
Any essential dynamic updates are communicated