Comment 2 for bug 280950

That behaviour is reproducible indeed. But it seems to be the intended behaviour of OOo interface.
Therefore, the "highlight" icon button only applies highlighting (using the least recently used color) but never removes it.
Maybe that behaviour is a little surprising from the point of view of a user; but apart from submitting a feature improvement request upstream, I do not think something can be done at the Ubuntu level.

Perhaps an improvement would be that hitting the button when the selected text is already highlighted (with the same color) actually removes the color instead of reapplying it (a no-op in this case). Dunno if that would really be felt as an improvement for every user. Advice?