i have some delicata squash growing from last years seeds. all the other plants have produced normal squash. one plant has produced dark green squash? mutant? will the color change as they mature?

Did they all come from a seed packet? Or did you save seeds from one you bought or grew?

If purchased seed, well, mistakes happen. It will be edible; other qualities may vary. It could still change color- pumpkins change late.

When you save seeds of any squash, there is potential for crosspollination. It depends on just which other squash plants were in the 'neighborhood. where the first squash grew. It won't make any squash inedible, it may affect color, shape flavor.

I had a warted pumpkin/ squash last year and saved seeds from it. Thing was really big, and orange like a pumpkin. Have only three plants from it. Two are white like the lumina pumpkins, and one is very dark green with the Cinderella shape, and slightly warted. Not one like the original.

I once saved some Zucchini seeds after growing them next to pumpkins. My "Zucchini" plants ended up with short vines and pumpkin orange fruits that were hollow in the seed cavity like a pumpkin.... but that is how I end up with so many goofy things in the garden- and it is actually fun growing odd things that nobody else has!

these are seeds i saved from last years fruit. it's funny because all the other plants have normal fruit.

That's genetics for ya!