Is using Gray 4 month old discard ok?

I took out some 4 mo old discard that I had left in the back of the refrigerator. It’s not moldy, but it is kind of a darker gray with a bit of hooch on the top. That’s also gray. I stirred it together, and then added water and flour to feed it. I’m just wanting to know if it is ok to use it when it’s that color? It does look like it’s going to rise.

It's probably fine. If you add flour and water and it bubbles and looks and smells right, it was fine. In the unlikely event that it doesn't do those things, it wasn't.

I frequently leave a "backup starter" lurking in the back of the fridge, and it doesn't look terribly nice when first pulled out many months later, but is nearly always fine.

Gray is unconcerning, in my experience; pink is one I'll throw out without remorse, but pink does not usually happen in the fridge - more commonly from unfed-for-too-long-at-room-temperature (when it's very nice to have a backup in the back of the fridge...) Generally the gray goes away with adequate feeding (you might think it wouldn't, but it does.)

Slightly out of focus, a merely week or two old (well, since its last use - it's 8.5 years since starting it) gray-ish starter:

Same starter after feeding, 2.5 hours later.

I've got a reserve backup I'll need to wake up soon I'll try to get pictures of, as it's likely to look a lot more like a 4 month old one, being many months old, possibly a year and a half. I expect it to look awful and be just fine, and to look fine after feeding.