Well, if your talking light then green is a primary color and yellow is a combination of green and red (also a primary color of light.) If you are talking ink, then yellow is a primary color and green is a combination of yellow and cyan (blue, also a primary color of ink)....... Oh wait, you are talking about the packages or the blades themselves?
Sorry, I couldn't resist
I ride a motor scooter most of the time. I get between 80-115 miles to the gallon when I do. On those rare days that I drive my old beater of a car, I get 8 miles to the gallon, YMMV, mine sure does.