The middle is the grey card the green is pretty much spot on and it has a little more red and blue is not that much off. Overall I'd say pretty much even.
Lastly it's the coffee filter, like the grey card it's pretty much spot on but clearly lacks a lot of red and there's too much blue.
I've seen some test photo of the coffee filter and it turns out great! I don't know if maybe I did something wrong but this is only a quick test. Will do another test hopefully with a expodisk and/or and expodisk alternative like what phottix is offering.
btw here's the set up of the test (credit of the picture to me, Jonathan James Tan)
tested with mix lighting (overcast day, indoors with tungsten lights), set on manual at ISO400, 1 sec and f/8
the grey card and the coffee filter