Some of the leaves on my large kentia palm started yellowing. It sits indoors in a low-light corner and I'm in San Francisco, where it's been cooler and darker lately, so I've been waiting until the soil was pretty dry until I watered (a month or so between waterings). The drainage of the pot is good. The water goes through almost immediately and I quench it with a gallon of water, let it sit for a few hours, before putting it back in the pot.

I noticed the yellowing when I went to water it yesterday. After watering, I think one of the fronds may have turned even more yellow. I'll post more photos when I get home.

What could be the cause? Is it root rot?