You are correct. I have been wearing 'Dickies' work clothing since 1970. Back around the year 2000 , it became cool and stylish to wear Dickies stuff by the younger crowd.
If you wear blue jeans, your tee shirt can be any color. But if you wear any other fabric, your tee shirt must be ... I'm not sure what, but it can't be just any color.
That doesn't matter much, because only jerks will tell you about their opinion of your choice. If you are wearing jeans and tee shirts, you really don't care about anybody's opinion.
I learned that people are stupid that they buy clothing with names on them that are made at the same sweatshops in China that the Walmart clothes are made and are willing to pay ten times the price. Go ahead and trash the sentence...I get like that whilst standing on a soapbox.