Apologies for that, Ekename. I can't seem to edit the OP now for whatever reason; do you think it would be better if I delete it and re-post it with a space in between the last colon and the question mark, or keep it as it is? (Apparently the colon and the question mark automatically turn into the emoji.)
Anyway, thanks for your help. I thought of <i>colonate</i> too and asked the OP, Pete, if that were the answer early on.
He responded that the solution didn't actually have to do with the word <i>colon</i> but rather only with the two-dot symbol.
But many thanks!