I'm no expert either, but those droppings look very normal to me. IF you are concerned, I would recommend an avian vet. I've taken mine to a vet that saw birds, and it was a waste of money. Definitely seek out an avian vet, if not for anything else, future wellness visits.
They are both doing okay. They are still sleeping a lot during a day, but they seem much more active than before too. Chestnut flies out of the cage every other day which I'm happy about, as he's exercising. Their poop is back to normal colour (no more green and watery), which seems like a good sign.
I started to think that they might have mites, as they are really restless when going to sleep and they itch a lot (could be due to the moult, as that just kicked in full on). They use their perches to rub their heads on them several times a day- is that normal? There are no obvious signs (crusty beak, or black dots etc), but it would explain sleepiness during the day too.
Also Ocean's tail is shaking sometimes, when he is resting. I haven't noticed it before, but now it's quite obvious. I read that it is also a symptom of mites, is that true?
Still no success in finding an avian vet in this area, and don't feel like going to the exotic one again, as it was a waste of money.