[Projects beta] [Usability] Delete button could be more obvious

[DanCarterGMSL]

From a project board, I clicked on an issue to open the sidebar. I then accidentally clicked "Delete from project", which brought up the following popup:

This was very useful, as clicking on Delete was an accident.

However, I very nearly clicked on the "Delete" button, and only realised that I actually wanted "Cancel" at the last second!

I wonder whether it would be more obvious if the Delete button had a red background. That way it's more obvious that Delete is a dangerous action, and that Cancel is the safe option.