Leek is a perennial herb vegetable and one of the perennial green leafy vegetables.

Leek yellow is a kind of leek that is isolated from light and grows completely in the dark. Because there is no sunlight supply, photosynthesis cannot be produced. When chlorophyll is synthesized, the grown leek will turn yellow, which is called "leek yellow".

So leek is green and leek is yellow.

Experiment. . . You plant two leeks, one sees the light and the other doesn't. Grow up, one is yellow and the other is green. . . When you grow up, put alcohol in a small beaker, add water to another big beaker, put the small cup into a big cup, light the big cup with an alcohol lamp, heat the alcohol, and boil the leek (green) in alcohol, and chlorophyll will come out, and the water will turn green, but the leek will not. . . hum

I typed so many words. . . Hmm. This seems to be an experiment in the biology class of senior one. . .