James35 and all,
Have look at
Take the RC racing link on the left and then choose "preislisten" on top, there you will find everything you need...
It's a German manufacturer, he has the whole range for donuts(&mounted) for I believe everything that can run on foam... He doesn't use the color codes just shore ratings, for my 12th scale I have almost ordered his full range (donuts only)
For Indoor(Europe - odourless) I go with shore 30 or 36 allround, maybe for higher grip tracks you can go for the harder compounds. I used to go with the CRC tyres but they are more expensive and it takes longer to get them here in Europe.
In my case (and I ain't that good +/- 1,5 sec a lap slower than European Top-drivers... but I'm gettin' better
) laptimes were similar, just needed to test different compounds to balance my car(CRC CK3,2R) again
Nice guy to work with, E-mail him as ordering online was not possible some weeks ago. He will reply to you quite fast. Also shipment to me (Belgium) was very fast, cheap and accurate, he even gave me an extra set to try out... (think it was some double compound, but don't have wheels for this right now)
I hope you can do something with this, I know its a europe thing but hey it works...