These cards are exactly what you need for this effect, and to do multiple color changes. Cards reverse one at a time
.. then then change to different cards..then the backs even change to surprising colors..

I do use the same move in many other tricks now. After three or four days of practice I think I am better than any videos on YouTube. They just don't do it any justice....
It also might be a little overpriced I got it on open box so for that it is well worth it for the method. These were made to look like bicycle cards on the back without infringing and they do look pretty cheesy to anyone who knows cards

very good quality, the cards are plastic and are very thin (think nilon) made to during in the time. I already had a version of this effect but this type of cards are best.

~~Quick Review~~

Special Cards Quality - 3/10
Routine Quality - 4/10
Instructional video 1/10

~~Longer Review~~
(Please take note, I am not hating on this product and this is my completely unbiased thoughts on this product)

~~The Cards:
These are super thin plastic cards. They slide easily and are durable. But that's about the best I can say. The printing of the backs is super blotchy and incredibly low quality. As if a person made a silkscreen of a really bad-resolution graphic of the standard Bike Design, And printed it on a silk screen with larger-than-normal holes in them so the ink just blobbed out. The face designs are equally as awful. The text appears to be more for comic books as it has a handwritten appearance to it. The colors are so dark it's almost an assault on the senses.
No respectable performer would ever whip these things out. This falls more into Creepy uncle territory.

~~Routine:
I have watched the video and the instructions (More on that later). I for the life of me can not explain what the point of the routine is. And the description of the product is off as well. 4 Blue cards are shown, They turn face up to reveal They are the 4 aces. As the aces turn back around, the blue cards are revealed to be the kings. You flip the Kings over to show their blue backs, Then one by one the cards change color. Green, to black, to yellow, to red. Then you just lay them awkwardly on the table. The handling show is super awkward and the performer drops one of the cards at one point. But I'll express more later on what you can do to make this better. But it's just not a good routine.

~~Instructions:
WHAT THE ABSOLUTE! I feel this video had someone talking, but they just edited it out and added music that in no way shape or form went with the content of this dvd. First you have 3 options at the Title Screen. The performance, the instructions, and a demo loop. The demo loop did nothing that I could tell.
So The Performance is Ok. Looks a bit odd, the handling is a bit odd as no performing magician handles cards that way.
The Instructions is when things get Really wild. Like I mentioned before, it really feels like there was supposed to be talking but they edited it out. Words can not describe the absolute mind-melter I can not explain how this video goes, it feels as if the instructor is trying to figure out what is going on most of the video. The Instructor at times seems as if they are going into a completely different routine. It does not make sense at all.
There is 1 (one) Slieght in the entire routine and it's by far the worst move I have ever seen. For example, If it was a double lift, the double this person would use is bending the card almost completely in half. This takes a Pinky break to the realm of Jamming your entire pinky and ring finger to hold the break levels of absurdity. None of the sleights I mentioned are in the routine. It's an example. Honestly, I don't even know if the routine is fully taught as I was losing my mind trying to figure out what was happening in the video.
I am doing my best to try and find something noteworthy about this product, but I have nothing. It really is that bad.

~~Final Verdict:
I hate to be mean, but this is 100% landfill-worthy. This is the kind of thing an inexperienced hobbyist would pick up from a magic flea market or from a Magic lot sale online. There is nothing redeeming about this product and if you fancy yourself a good magician, you will avoid this product at all costs.
This product 100% should have been put in other people's hands and worked on before it ever touched the market.