When on the line back at Ford in 72 or 3, one of the jobs I had was putting all the seat belts in the L side of the car. 56 cars an jour meant one had to hustle. I saw a Pink Pinto hatch coming and thought has to be a black or white interior either of which took black seat belts.
So I grabbed a set a black belts before the car got to me thinking I'd save a bit of time. WRONG!!! When the car hit my location it had an Avocado green interior
I remember that story being told in here. On a related note, Dad tried to order a Bonneville Station wagon with 421, 4 speed wide ratio and bucket seats, it was an available combination. Dealer refused to accept the order rightly figuring if Dad refused it they'd have an unsalable white elephant on their hands. Manual transmission alone even back then was not a popular thing outside of hot street cars.
I suppose they'd have accepted the order if he paid upfront and accepted the car no matter how it'd been built, that sort of thing happened, not every option was always available throughout the model year.
In 2007, I tried to order a then-new Mustang GT, manual trans in Legendary Lime with tan cloth interior which was 100% a valid combination. Dealer told me the same thing - if I don't buy it, they'd have an albatross on the lot. Wound up buying a groovy little Hyundai Tiburon which I still have.
And then in 2016, when I went Mustang shopping again.... Wound up going to the big city since the combo I wanted didn't exist - Deep Impact Blue, Cloth Guts, 6spd, GT Base.... there were only TWO similar in all of North America - one in Winnipeg with Recaro's which I didn't want and one in Tennessee with an automatic. This time, they placed my order through the factory without a second thought. They even had 16-other Mustangs on the lot .... but not a single blue one. I think that was my saving grace. Had there been something blue on the lot.... they probably would have steered me toward that.