Agree on the tailpanel, however the grille color might be dependent on the paint color. There is a fellow on here that now maintains the m-code cuda registry, and it is not available online. If he doesn't chime in soon, PM me.
In 1969 the color of the car had nothing to do on the color of the grills. Starting in 1970 the colors of the grills varied with the color of the car but at that point the barracuda was an E-Body.