While it is true that the base interior "white" for most Broncos was Wimbeldon White, I have never found that it matches the dash color very well. The dash appears to be slightly yellower. And it is not due to yellowing of Wimbeldon White, since buffing/compounding does not help either. About two decades ago I found that a near perfect match was a GM 1980 colorwhich goes by the following names depending on which model/make/division
Chevy-Frost Beige
Buick-Beige
Oldsmobile-Beige
Pontiac-Stetson Beige
Cadillac-Flax
Corvette-Frost Beige (78-79)
It is perfect for touching up the nicks that occur especially under the ash tray, as well as anywhere else. I still have a can that I bought way back when and it still works well.