Flash or sunlight really brings out the true color of the eggs. They may not look their darkest, but you get a true look at them.
The Bergs Fairytale garden on FB has some of the finest looking dark and colored eggs. Some are charcoal gray, almost black. I complimented their eggs and said I would love to see a photo in the sunlight. That apparently offended the owner and he gave me a talk about UV and photography lol.
I’ve got 3 or 4 eggs in this group that have a bloom, but most are the smoother glossy finish. I’m hoping the ones with a bloom will make good olive eggers.