According to post #16 here, your truck was supposed to be white on the outside and and medium blue inside:
http://67-72chevytrucks.com/vboard/s...d.php?t=324793
Does the vin match the vin on the truck? Does it look like its been messed with?
Blue on the drip rails could have been from overspray from the interior painting? Not sure about the grille. maybe it was swapped. Have you found white anywhere on the outside?