This site states that number is a custom color code for Coronado Gold (although you do not have the 867 prefix). Scroll about half-way down to the Paint section.
http://www.1967gto.com/data_plate.html
UltimateGTO says it's the same color as Tiger Gold
http://ultimategto.com/66colors.htm
That's a great color option to have, especially with a black top.