Woody,
This matter is still not clear to me, either, Denny Graham has helped us the most with the modern color for interiors prior to 1954.
A tricky aspect of this is that "break" between 49 and 50 was not "clean" - people have reported the pre and post interior colors being used in post and pre years.
Furthermore, dublenaught has posted above that his cab has Pearl Beige paint - a 1954 color according the GM. However, it seems that just about anything is possible when it comes to truck plants switching from the old paint to the new paint (they switched whenever the old paint ran out, it seems).
Tim
