I recall having such a deck in the early 60s (in the days of my youth!)

I can't recall the effect exactly! I vaguely remember it being a R&S deck, and that the spectator picked a card and the reveal was that the colors had reversed, red clubs and spades, black heats and diamonds.

Does anyone recall that deck and what it was called and what the effect actually was?

TIA
Phil

I've done a little more research and the description of Aldini's Harlequin deck described in "Roughingly Yours" seems to be similar. However, I had the deck in the early 60's and "Roughingly Yours" was published in 1969 -- by then I was "retired" from amateur magic.

Phil

I found it! It is Hull's Coo Coo Cards!