I have found this guide over internet.
Yellow and wilted, faded and droopy, dry and crunchy, edges and tips yellow, misshaped leaves, discoloration, white stripes...
Seems I'm missing 'brown' in there.
I like giving Space a hard time as much as the next guy, but you're being a bit pedantic.
Brown leaves are what you get after they turned yellow because you didn't fix the problem. Palmer called them brown, but there's plenty that are yellowing from the top.
Palmer, how much water is the soil retaining? JMs hate having wet feet, which combined with the evidence is why I ask.
Of course, if it's autumn there... well, don't worry, the leaves will come back in the spring.