What is "shade of green"?

Thank you
Visit the paint section of the local store and look at all the paint colors available. Even within the green section, even within the part you might call "pale green" you will find dozens of colors.

literally, one color (or shade) of green
Students: We have free audio pronunciation exercises.
Oh.. this thread should be similar to the one I'm gonna ask.

A: Which paint color did you choose for the waiting room?
B: A shade of pale green.

Q) Why the speaker B says "A shade of pale green" instead of simply saying "pale green"?

Q2) Is "A shade of pale green" is the same way of saying "a pale shade of green"?
 BarbaraPA's reply was promoted to an answer.