I just finished reading it. I have to say, I simple adore your writing style. It’s so fluent and immersive!
Onto the actual story, I really enjoyed it. From what I could see, everything Bill was used to in Dickey’s Diner was changing bit by bit - different waitress to usual, different lipstick being worn by Doris, and then the Jukebox being switched off.
I’m not exactly sure what the specific detail is, though? I might give it a quick reread, though.

Ooh, looking at your comment @rayofsunshine and the "Last sunday and the sunday before that" is he in a sort of time loop?

Oh.... at the end I think he's having a stroke or something similar?

Thanks for reading @rayofsunshine and @creativedragonbaby !! My main question is what you think the reason is for Bill to freak out about everything changing? I love hearing all the different interpretations before I explain my intent

I believe he's an older fellow and that he's clinging to the past. That's why he visits a small, older diner.
Does he have a mental illness such as autism? That can make people often very particular about things.

I probably shouldn’t say it’s an illness.... I have autism myself

I thought it was some sort of mental illness, or maybe an intellectual disability of some sort? I wasn’t entirely sure, though.

These are all really good! I definitely see where you get the disability/illness from, and thanks again for helping! As for my main intent, was there any point where you might have suspected that Bill could be blind now? I know I left it super vague and I'm trying to figure out how to make that a little more recognizable (not to make it the definite reason, but just to make it another possibility)

Oh wow! Actually, that makes perfect sense now - with him mixing up magenta and bubblegum pink.

Yeah I did think that he got blind towards the end but it seemed as though he became blind halfway through.
The descriptions of appearance were so detailed and convincing I thought he could actually see them...

1st paragraph: "yesterday's crumbs" ....and he likes this place?! I get the crumb/gum thing, but yesterday's?! No thanks XD
"Why not just drive off a cliff instead?" That made me literally laugh out loud, you can really feel for Bill... ol' man just trying to go enjoy a piss...
Anyway, yeah, I'm going with the stroke that induced blindness theory.
You could also add deafness; don't have the customer ask to turn down the jukebox, just have him go deaf as well. That'd be fucked up.
As for why the change was nagging at him, dementia popped into my head. Even the slightest change around the house would send my grandma into a rage, especially if it were something specific, like if someone moved specific pair of one of her ten pairs of glasses and she were seeking that specific pair out? She'd go ape-shit. What's funny is she'd spend the day moving everyone else's shit around because she didn't recognize it as her own and she felt it needed to be organized. I once lost an entire....(1/2)

backpack full of clothes that way.
In summation, I really enjoyed that short story, and while it was obvious the stressing of the colors from the beginning (great job on that, btw), it didn't give away the twist and the significance of stressing those colors early. It's only with the "where's the jukebox?" where it starts to sinks in. If he was just going blind though, if he's so familiar with the diner, he should easily be able to reach the bathroom on muscle memory alone.... another reason a stroke might work better. I also liked this foreshadowing... "Good as it gets." - Bill.
Seriously though, great short story.

Oh... and with the loss of appetite, that's another sense that failed him. If you want his senses to rapidly fail even more, have him suddenly stop being able to smell the diner as well.

Sorry Bill, you got fucked up.