In my wanderings about the net looking for original parts to many of our trucks, I found that used 1946 inner fender panels and splash aprons all for the most seem to be a semi-gloss (or satin maybe) black like the below pic.
Others with 1946 trucks should be along to chime in on their own trucks and experience/knowledge soon.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)