I have seen nothing like that, but I am shure I have not seen everything in tw5 yet.
what do you hope such a feature to do for you or represent on tidders with such a feature.
I have been considering the idea of using a field to indicate tags (From available tags) to display in the view template so that you can simply toggle them.
further allow you to select one (or), or one or more (And) from a set of possible tags. the tags can have a colour set so it may approach what you are asking for.
I want a generic solution to setting a tiddlers status, project name and more.
what is your use case?
I am still a way from making this happen.
regards
tony