Change the colour of the 'Unpublished changes!' warning bar

Unfortunately our users often miss the 'Unpublished changes!' bar on lists as the yellow colour makes it look like a non-urgent 'status update' (like the blue bar 'A review has been request') rather than an important alert that they need to do something.

Please change the colour of the bar, such as from yellow to red, to make it more obvious that an action is required.

Also make the bar float and change the wording.