The 1954 truck engine is a (medium) gray color. It is supposedly a different color than that used on 1953 and earlier truck engines.

The Filling Station lists the same engine color for 51-62 Chevrolet cars and trucks ("blue"). This certainly cannot be correct for all those years of 6-cylinder cars and trucks - in at least 1954 (and later) the car 235 was called the Blue Flame Six and it was undoubtedly painted a different color (blue) than the truck engine (gray).

Here is the 1954 truck engine gray sold be Jim Carter.

Tim