selectable colors for highlighed text

It would be good if the color of the highlighted text could be changed so that the highlights represent different contexts.

In Adobe Reader i use yellow for central statements, red for important quotations, green for examples and blue for definitions. In my opinion, it makes sense to have something like this in Memex.

A competing product, LINER has this. It was one of the features that made me take so long (about a year after I discovered Worlbrain) to start using Memex.