Scoring less than 100% on more than one cone does not mean that you have more than one defective cone. Your defective cone is the one that you score lowest on. Sometimes, people also score below 100% on their non-defective cones. This is related to how the brain processes color by combining the signals from different cones, which in some cases can make it more difficult to see images targeting a non-defective cone as well. Additionally, the blue cone can lose sensitivity as we age, leading to lowered scores.
