Here we have a "capped" frame of honey that's ready to be harvested.
The bees are working hard. Here is a frame of partially capped honey.
I love this picture!
The top outside corners are capped honey. Its lighter in color because once the honey is capped they bees don't walk on it much.
The "open cells" have green, uncapped honey. You can see the glistening in the picture if you look closely.
The light tan area in the center of the frame is capped brood (new bees) that are being raised.
That wax is darker because the bees are walking over it all the time taking care of the young.
Its literally like not wiping your feet on the rug before you enter the house. The bees track pollen, dust, and anything else the bees track around on their feet and it gets left behind on the wax cappings.