I've finished a fairly straightforward interface that enables you to turn on and off highlighting for all the categories and subcategories in a text. It's pretty flexible and extensible, although at the moment the highlight colours for the base categories are hard-coded; making something self-adapting would actually make reconciliation between two encodings harder, because they'd end up with different highlighting. As it is, the base categories pretty much exhaust the easily-distinguished highlight colours. Waiting to see if EC can use this as it is, or whether she needs more features.