pale Lady Palms

I have some Lady Palms in 3 gallon containers. What causes them to turn pale? They used to be dark green.

too much sun, too little humidity, too little nitrogen (though unlikely in a potted palm), too little water. All or one... or something else entirely (like a palm that is dying).

i'll try moving them into a shadier spot. If that is the problem, how long do you think it takes for them to return to dark green?

the leaves that are yellow will stay yellow, but the new leaves may come in darker green

Giving them some magnesium sulfate cold also help. I know it did with mine.
Barb