Chris, I never used the AIR 10 version so I can't help about the purple dye still being used. I have a gallon of VP 10/22. From what I remember, I got it at a Baton Rouge contest over a year ago. It is "clear", not purple. So, it appears that VP eliminated the purple dye for this mix. There is an "item number" on the label but that may not mean anything, such as a lot number, to determine when the purple dye was discontinued.
I had a gallon of the purple stuff, I think it was 10/22, bought years ago. It stained the white dope finish badly. I ended up using it for bench runs.
I now mix my own. Oil (castor and Klotz) from Sig, methanol from Smiley's Racing, nitro from a local guy who supplies fuels to local race tracks. I never had a problem with the home brew and I can adjust the components as needed.