New growth looks good
Now if the problem your asking about is the light looking green to yellow on the lower leaves ?
And in general the plants look like there leaves are dropping .
Dropping can be stress do to heat or soil possible issues or can be light were out when you took the pic
Check list Environment
Temps
Humidity
Air flow
Then we look at feeding
Super soil ? How long has it been since they are in there pots ( plants could have used up all nutritional value is soil) plants are in soil about 1 month may need to do a compost tea
I am more concerned with the plants being droopy then the lower leaf issues