Gary, the seat-of-my-pants navigation intuition would be under “Exterior” since I tend to think of paint color as an exterior feature.
However, in terms of the existing layout it is probably best grouped with the paint codes under “Specifications” since that is where you have the color charts.
SHORT BED 4-DOOR DIESEL: 1986 F350 4x4 under construction-- 7.3 IDIT ZF5+GVOD
STRAIGHT SIX 4X4: 1981 F150 2wd to 4x4-- 300 I6 close ratio diesel T19, hydroboost brakes, Saginaw steering
BIG F: 1995 F-Superduty under construction— converting to 6.9L IDI diesel ZF5+DNE2