The greyed items stay greyed if I select other parts of the content.
Added the css to content.css and then realised this is only for the ckeditor editing window so added the css to the site css file.
Then found that some of the image borders where white but others remained black.
On further inspection of the source code all the image borders which remained black had "currentColor" in the style definition whereas those images which didn't have "currentColor" showed white borders.
I understand that currentColor will use the surrounding text colour, which is black, but why have some images got currentColor style and other do not? The client has not added any souce code, they simply added images through the toolbar. Is there a workaround so that all images have a white border?