What I referred to as the two-tone grille is the same as what others sometimes refer to as the GT grille. The whole grille is painted SG black, then the area between the large corral and the small corral is painted a SG metallic blue that is similar to the 67 grille color. I believe the blue appears darker than the 67 grille color because the blue is painted over the black. Also, the blue is only painted on the front of the grille. Some overspray made it to the back, but no attempt was made to paint over the black on the backside of the grille.
Regards,
Pete Morgan