I really want to like Spectrum more than I do. It has all the hallmarks of a great trick, in fact it is a combination of great tricks, Dai Vernon’s Triumph plot and the colour changing deck.
You tell your audience you have an amazing colour changing deck, and proceed to remove a blue deck from a red box. After apologising for the poor joke, you show the blue backed deck and ask someone to just think of any card they see, then the deck is mixed with half the cards face up and half face down as in Triumph. You deal through these cards to divine the thought of card, but fail to find it. The participant tells you their selection and you remove it from the deck.
In order to recover from failing to get their card, you demonstrate that now all the cards are now facing the same way, and then you ask them to turn their card over to reveal it is the only card with a red back. Then for the kicker you spread the deck and show all the cards now have a red back.
So there you go, three moments of visual magic with one deck of cards that do virtually all the work for you. It is very easy to do, as close to self-working as a Svengali deck is but it can so easily fall flat unless you perform the living daylights out of it.
The initial failure to find the selection weakens the trick as the subsequent ‘magic moment’ of the cards righting themselves isn’t strong enough and is disappointing and confusing after the expectation of a mind reading miracle. To get around this, you have to put a lot of emphasis on the mixed state of the cards which doesn’t make much sense or downplay this part and get to the red back revelation as soon as possible because that is more of a miracle.
I can’t help but think the colour changing deck kicker diminishes this contrasting red back moment. Traditionally colour changing deck routines like this end with the cards being a different colour to the selection, highlighting your participant somehow chose the only odd card, ending with all the cards being the same colour shows they could have thought of any card and it would have a red back.
You therefore have to separate the effects, and really make it clear the colour change happens at a moment way after the selection process. Almost as a different trick entirely, perhaps by recalling your first promise at the beginning.
The deck is a clever combination of gimmicked decks and cannot be examined but the final display of all the backs is super clean. The reset is under a minute and very easy.
Spectrum can be very powerful, but you need to play it well and it will take a few performances to get each phase to hit home. Make the mind-reading section fun and dwell on the odd back revelation as a miracle and do the colour change as a nice routine ending finale. Now I think about it, I do like more.
You can find Spectrum by Paul R Wilson here: https://monstermagic.co.uk/products/spectrum-by-r-paul-wilson