this is a quote from the road runner forum.

"I have done some research on this topic in the past, and what I found out is that the color changed mid year in 69. Early built cars had red, and later built cars had orange. Each plant had different amounts of inventory of the red tins that had to be used up before the switch to orange. So you could have either color on your 69 Road Runner. Use the color that makes you happy."