A green maxi skirt is a skirt, with a green hue, that length extends down to the ankle. It was designed and named as the opposite of the miniskirt, which was created and hit its peak in the 1960s.
Maxiskirts came about originally in the 1970s, but have seen a sudden resurgence in fashion relevance in the 2000s. Maxiskirts can be opaque (like a normal skirt) or slightly see-through with shorts or a shorter skirt worn underneath. Incidentally enough, there also exists the term of midiskirt. This design and term also came about in the 1970s, and refers to a skirt whose length extends down to the calf.