318 engine color

I had a simular problem with my car, the guy I bought my Duster from told me that it was a 340 engine he even had documentaion from an apraiser stating that it was a 340. I got the car home and my curiosity got to me so I compaired the engine stamping number to ones on yearone.com and unfortunately i had a 318 not a 340. I was so pissed off and upset. But down to your question the engine stamping will have the engine size in it. and 318 are blue.