This is not something I have a strong desire for, but I ran into the limitation on this trying something out, and I thought it could be a functionality other users might appreciate having too:
The markup feature for text (contrast, colour, font type/size) works nicely when the virtual tag is displaying in the main panel.
But when displaying it in the Column- or Thumbnail Browser, it doesn't function.
Which makes sense, because e.g. using a larger font would not work well and mess up the layout.
But, having adjusted contrast and colours would not mess up the layout there.
So it may be nice if for those panels the contrast and colour markup would be used, and only the font markups would be ignored.