Why is it that pea soup is a different shade of green than peas? (Peas being dark green, and pea soup being light green) Doesn’t it seem that they should be the same shade?
Because the cooked peas still have their shells on. Those are soft and dark green, giving the color to the dish.
But pea soup is made from green split peas. That is, they’re dried and allowed to split midway as they’re naturally designed. Then the hulls are sifted out. What’s left are little pale green hemispheres of dried peas. When their cooked back up into a soup, they’re color is the paler green of just the center of the pea.
(I know all of this from helping my wife make homemade baby food for CRB. Before cooking the split peas we sift out all the really poorly colored hemispheres. The good ones are pale green; the bad ones are generally yellow, but any non-green ones are discarded.)