Hi.Over all a nice looking rescue.Some questions first need to be answered.How long have you had this palm?Has it always been in that location?What is foilage pro food?Okay without those answers I will take a educated guess.I don't think you were lucky enough to pick up a rare variegated one.Lol!I have one.My guess by the picture is it has a iron(Fe) deficiency.Get some palm fertilizer, one with a good amount of Fe in it.

I've had it for about 6 years in the same location.Foliage pro is a complete plant food. http://www.dyna-gro.com  It should have all the elements needed for good coloration. . My 'rescue' has recently discolored. My other 2 lady palms( to the left) look fine. It's a mystery why this plant has started to discolor.

I looked at the dynagro page.I noticed all their formulas had very little iron in them.I still think you have a Fe problem.Dynagro seems like it is more geared toward roots & blooms.I would get some slow release palm fertilizer.

http://hillsborough.ifas.ufl.edu/urbanforestry/palm_disorders_key.shtml

Found this.Section C #3.You have a manganese issue.Now I rest my case!This one preplexed me.I learned something too.Now I can sleep.Lol

Is there a simple solution/specific product or substance I can apply that will reverse this? I wonder why the other lady palms look just fine? Aren't lady palms slow feeders?

The simple answer.Start using palm fertilizer.I don't know where you are,here in florida all big box stores sell palm fertilier.You can also just get some manganese.