Dark seeds

Yes. The "squeeze test" will sort out the good from the bad.

Genetics...when you think you've seen it all...think again xDD

Yeah you’re gonna get all shades of color from same plant, not a big deal. Like NB said, as long as they aren’t hollow it’s usually fine. I do a simple test and give them a little squeeze between my fingers if it looks underdeveloped. It it is, and it’s not viable, it’ll crush cuz it’s not developed fully. A good seed, however can withstand a bit of finger pressure.

as long as it isn't hollow, the seeds are likely viable if mature... color is of no consequence. they are all normal seeds. :P