If they have been trending 'darker' lately, probably need to ease up on fertilization a bit.
Another possibility: The substrate looks like it needs a bit more drainage amendments to it, like perlite or similar. A water-heavy substrate can make plants droopy after a watering. It would spring back up at some point after that, whereas overfertilization will just curl/claw the leaves.
Diluting substrate is your only option for over-fertilization. Diluting substrate will not solve the problem overnight. The nutrient content inside the plant will need to be slowly used up before it improves. Just give less fertilizer or water-only with a little extra runoff. This looks fairly early on in progression, so don't go crazy with the runoff -- this may make the plant droopy due to lack of O2 in rootzone, but a necessary evil in this context. Observe and react -- dark or glossy with clawing generally means too high of nutrient content going into the plant relativee to growth, so it piles up and causes issues eventually.
Back to substrate -- coco needs about 33% perlite and soil usually needs 50%,. (and sphagnum peat moss needs 50%). Since you are 60/30, that's 40% weighted average perlite, vermiculite or similar vs 5%.
Nothing you can do about that now. It'll still grow fine and you can have a good outcome, and you can have better outcomes in future with better oxygenation / aeration of soil.