This Conrail fact came courtesy of Bob Bucklew who worked for PC subsidiary Excelsior Truck Leasing, the company that actually owned the MOW equipment and leased it back to the railroad and was originally posted to the PCModeler yahoogroup.
"When CR was born in April 1976, we at ETL got the order for the new paint to be applied to trucks, locomotives and cabins. We bought the Dupont paint and applied it to a truck. Yuck! It looked like baby poop brown and we called Conrail and told them to come and take a look. I thought it would look even worse on a loco and told them so. They did come and we were told to hold off on painting any others. I understand a cabin car was painted brown too. Within a couple of weeks we got the order to change to a blue. Rumor is it was a 1969 Fiat blue favored by one of the VP wives at Conrail."
Bob also explained that the standard of painting high rail equipped units of all types yellow and blue as the standard vehicle color originated with Penn Central (just substitute green for blue) and continued into Conrail.