Green stripes are GT12 - the real European GT12 with the narrow rear tires, not the American bastardized version of GT12.

Purple stripes (or blue stripe JFT) are the spec tire almost everywhere in the US for all 1/12th scale classes, except modified. Contact's version of the purple stripe tire is the best value. DiscountRCstore.com sells full sets for a little over $16.00. racing-cars.com may be a little less expensive after currency conversion, but they have been out of stock for a while.