That is more sheds than I have found in my life Ron. Impressive!
I think I could increase my find rate if I got out somewhere where you can actually see the ground rather than just brush but I'm lucky if I find a few a year.
two years ago I found a giant buck antler that had been chewed on. It was a year old and tucked back under some trees. I searched for the match that year and again last year to no avail.
Then this year I was back in the same area and stumbled upon the match laying in the wide open! Unchewed and has 9 pts counting the eyeguard!
I found a BIG 5pt on Feb 15th and my buddy Kyle found an equally big shed the same day in the same area...but both were left sides.
I went back 10 days later and looked for my match and finally found it 1/4 mile up the ridge in some big timber with tons of blowdown and debris on the ground.
Yes, they're naturally dark. Many of these bucks never see the light of day all fall. If the get enough rain/snow/sun then they'll start losing the color.