Columbo The Blue Key

[uncle al]

I am sure I saw an episode of Columbo eons ago which had him catching crooks because they had worn blue clothes and were invisible against a blue screen (chromakey,just like the weather maps and weather  presenters)

I've never seen this again and can't find it in epguides or anywhere else

Did I dream it?

[Lez]

It could be `uneasy lies the crown`.Columbo caught out the dentist because of a blue laundry substance.