candling dark colored eggs

[Cluky]

hello, so I am by no means someone who is experienced with incubation, but one of my hens went broody so I decided to to crazy and stuck some eggs under her. so far she has been a pro, BUT I have hit a bit
of a snag because without thinking forward I stuck some very dark eggs under her and doesn't look like I can candle them well now. so anyone know how I can figure out if things are going ok? weight of egg? stronger light?

 

[Sphinx]

Either use a stronger light, or just don't worry about it.

When I hatch FBCM marans eggs, I usually can't see inside. I do the occasional sniff test to make sure they're not smelly, and otherwise, I just leave them be and hope for the best.