I mean people had ways of getting things before amazon.com.
Here is a thread of people nostalgiating about fabric stores: https://www.quiltingboard.com/main-f1/good-old-days-remembering-old-fabric-shops-t133050.html I certainly bought fabric from brick n mortar locations and it is still the preferred method in a lot of situations.
A fabric store, especially one in a textile/garment district, would have been able to do special orders of cloth or dye. They would have had networks of suppliers large and small to call upon. It somewhat strains belief particularly that gays would have been unable to obtain any given solid color of fabric given their longstanding ties to fashion industry. Another group, maybe. But come on.
Unless there is something specific about this color, at this moment in history, to explain it. I looked up briefly the history of pink dye and all I found was what I already understood to be the case: pink is a particularly easy color to obtain.
what're they going to do, fine them for 3% of the money they made?