Sometimes this is just the nature of the beast - Early Girl tomatoes do not ripen all in one shot when the days start to grow shorter the end of the season. The good news is your tomatoes will continue to ripen after you pluck them from the vine so the yellow should turn red as the tomato continues to ripen. This late in the season try to keep your tomato plants dry - wet leaves slow down ripening and can cause a deadly leaf blight disease. Some gardeners place their pots close to the house in late August under the eaves to protect them from the rain. Keep growing, Marianne Binetti