[markwilliamson2001]

I think the Fastrax ones are slightly lighter foam, so a bit softer than the Snee Blues (but you can't buy the Snee Blue's anymore).

I tried the schumacher blue and green, and the schumacher Blue are okay for most tracks (indoor and outdoor). if you are lacking traction, the softer foam (schumey green) maybe better, or in a harder (Schumey Blue Compound) tire, which does not require as much support.

For yellow minipins and grass, run the schumey/Snee Blue. Edit purple is also used by craggy at the moment I believe, which is also similiar.