91s are different from all other years, at least the early ones are. Do you have the coathanger anchors, or the cast/plastic coated anchors? I have a couple of the coathanger variety, but they are not the 91 tan. The 91 tan is known as camel. It is also a 92 color, and maybe some 93s have it too. GM went to a darker tan for some, or all of 93.
They are not a wear item, and painting them to match would last a long time. (SEM paint is recommended)
67AN Light Camel SEM#4605
67BN Medium Camel SEM#4607
67BN Medium Camel (Vinyl) SEM#4617 This is probably the correct color.