[Standards] Occupant colours

I quite like XEP-0392. I didn't honestly think I would when it first proposed and published, but it's really handy. But, XEP-0392 doesn't - anywhere - specify what the "input" should be. I can see some options: 1) Pick the relevant jid. I'm currently using the bare jid for 1:1 conversations, and the XEP-0045 occupant jid (including nickname) for MUCs. That seems the most obvious, but means nickname changes also change colour. 2) Pick the display name. I could use the name for 1:1 (the one I display, from Roster etc) and the nickname from a MUC. That has the advantage that where those are the same, the colour will be consistent - "Zash" will be coloured the same on all MUCs, for example. 3) Pick the most stable identifier I can. So occupant_id in MUC, though still bare Jid for 1:1. This would mean the bright pink occupant would remain bright pink no matter what nickname change they tried. No escape! Any suggestions? Or doesn't it matter? Dave.