I've been using 10/22 exclusively for the last few years; there was one deep purple run after which the fuel has been perfectly clear.I think they had an accident measuring the dye: I know that when it happened they changed the formula from "supposed to be light pink" to "it's entirely clear, we promise!".
Near as I was able to determine, it was on purpose. They ran out of red, so they picked something else. They tested it for staining, and no stains. On Monokote. Brett
At one time, Roy's Hobby Shop in Hurst stocked Powermaster/GMA. I have not checked on that for a while as I now make my own home brew.
There is a race/speed shop on Kennedale Pkwy (Kennedale) that sells methanol for $3.50 a gallon. They may have nitro as well but I had already bought some ($25/gal) from another place in Grandview. I hope Sig continues to sell the Klotz and castor. With shipping, a gallon of each came to about $44 the last time I ordered. That same oil is about $15 to $16 a quart in motorcycle shops and other places.
I spoke with the people at Powermaster: they said that they have GMA 10/22 in stock....David Fitz did a lengthy piece on Stuka about how to make the current "Airplane" fuel replicate 10/22