When did Colorado last hold a presidential primary?

A:

Colorado held presidential primaries in 1992, 1996 and 2000. In 2003, lawmakers passed a measure to eliminate the presidential primary as a cost-saving measure. The estimated savings generated by cancellation of the presidential primary (which was closed to unaffiliated voters) was $2.2 million. It is estimated (conservatively) that restoring a presidential primary could generate 10 times that amount in economic activity.