for Corally tyres,i use Gold rears with silver fronts,seems to be the most popular with Corally Drivers,gold rears & gold fronts are o.k has well,if you want more life out of your tyres then try silver rears,like i say the most popular for carpet is gold/silver rears with silver fronts.i think for out doors people use Green rear tyres,
Also if you check out the uk corally site,they have a part all about 1/12th corally tyres...
cheers
stevie