This should be simple to implement, and I'll explain my issue with the current system. When I'm composing a reply, I often cut\copy\paste segments of my reply as I'm restructuring it. When I do this, I must choose to paste as plain text or else it will copy the source formatting of the composition window, which you can see formats the text with a white highlighting. This has caused several of my well formed replies to come out looking flawed. It'd be great if the reply composition window had a button to switch to plain text.