Leaf Is Yellow, Brown And Purple-Red!?!

[HopefulAlligator]

I'm HopefulAlligator, AKA Allie. This is my first post here, thank y'all for having me.

I've had orchids before, but it's been years. I've been planning on getting more, and today I made a big leap and decided to buy and try to rescue the few orchids I saw in the 'bargain bin' at my grocery store.

They all seem mostly in decent shape: a few yellowing leaves, a bunch of cracked tips, most things typical of stressed and mistreated orchids. I have well-ventilated, heavily-slotted pots and a bag of good mix on the way, so repotting will be happening as soon as they come in the mail.

The main concern I have is one has a large leaf that is yellowed all the way from its base, but has brown and purple-red coloring near the tip. (See picture for coloring and size specifics.) It is slightly droopy, but still plump. I've been looking around online ever since I got home, but I can't find anything like it. She has one other leaf that is yellow, however it seems to be a natural loss of an old leaf, as it is also drying.
Is this something I need to worry a lot about?
Is cutting it off the best course of action?
What will happen if I cut it vs. if I don't cut it?
Do I need to keep her separated from my other babies? (It's not squishy or slimy, just indentations in some spots.)
I hope I'm not being obnoxious with my worrying. I just really want to give her a good life and address her problems ASAP so she has her best chance. So I'm stressing a bit.
Thank you all so much!
-Allie

[estación seca]

Welcome to the Orchid Board!

That happens. It's losing an old leaf.

You can learn about growing Phals in a sticky thread here. From the left yellow menu choose Forums then Beginners. Bear the top look for the thread The Phal abuse ends here.

[SouthPark]

True. No problem at all with this one. And also - your question about cut versus no-cut -------- orchids growing out in the wild won't have anybody to cut them. So that old leaf would usually just dry up, and then eventually it would naturally drop off.

In our own growing area - if the leaf dries right up ---- then the base will generally disconnect at the slightest movement or touch. And then we can just remove the old dried leaf. No need to rush to remove it though. Or just remove it if or when it naturally disconnects and/or drops off from the plant.