The language appeared on the ballot as:
“Shall there be an amendment to the Colorado Constitution to declare that the English language is the official language of the State of Colorado?”
Source for Popular Vote data: Colorado Secretary of State. Abstract of Votes Cast, Colorado Secretary of State (http://www.sos.state.co.us/pubs/elections/Results/Abstract/pdf/1900-1999/1988AbstractBook.pdf) (accessed 28 Jun 2016)