A Spoiler is:

A non-winning candidate whose presence on the ballot affects which candidate wins.
The Spoiler Effect  displays the failure of the present Choose-one Plurality voting method in Colorado by terms known as Independence of Irrelevant Alternatives. Approval voting and range voting satisfy the independence of irrelevant alternatives criterion.
Complete information and examples found below

Colorado’s newest party is seeking citizens of the state to register to vote as Approval Voting Party members.

The Approval Voting Party has been established in Colorado. As a Qualified Political Organization we lack the ability to nominate candidates for the ballot until we achieve one-thousand registered voter members. The state reported 838 registered members at the end of July 2019 and the party was founded earlier this year.

On June  2nd of 2019 the first statewide convention was held in Denver.

Voters naturally want to choose more than one.