Extra-virgin olive oils can vary in color from intense green, to green with hints of yellow, to intense yellow with hints of green. The color differences depend on many factors: above all, the variety of olives and their ripeness, but also the type of extraction machine and the way it is used. By itself, color is not an indication of good or poor oil quality, except for red tones: these are caused by chlorophyll degradation and beta-carotene, and appear when oil has been exposed to light. In this case, the green color of chlorophyll fades, and the dark-reddish color of carotenoids become visible (while usually they are well-masked by the green chlorophyll).
Whether direct or indirect, light damages oil’s chemical, physical and organoleptic characteristics. For this reason it is important to store it away from direct sunlight or bright lamps. For longer periods of time, a dark, cool storage place is preferable. Incorrect storage of oil before sale (for example during loading and warehouse storage phases) can be equally as damaging.