It’s actually a somewhat solved task, by editors that support LSP. I can’t think of a UX that would work well for generally colouring identifiers distinctly th

It’s actually a somewhat solved task, by editors that support LSP. I can’t think of a UX that would work well for generally colouring identifiers distinctly though. One nice feature that does exist is selecting an identifier and highlighting other instances of that identifier (semantically, not just by string matching). This makes actively reading code a lot easier. It would be interesting to see this extended to allow multiple selections.