Colorado voters have a lot of options if they want to help nominate a major-party presidential candidate this year — but some may need to act fast to meet an upcoming deadline.

The last day to change a party affiliation — or to withdraw a party allegiance to become an unaffiliated voter — is Monday, Feb. 3. To do so, visit www.sos.state.co.us/voter.

Colorado’s change to presidential primaries from a caucus process offers more voters the chance to participate, but their options will depend on their party affiliation, or lack thereof. Registered as a Republican, but want to help choose the Democratic nominee to take on President Donald Trump? You can do that by becoming unaffiliated.

Likewise, Democrats who would prefer to select between Trump and his Republican challengers can drop their affiliation.

Ballots for the March 3 primary election will be mailed to voters starting Feb. 10, distributed this way:

Democratic primary ballots will go to voters affiliated as Democrats as well as unaffiliated voters. Seventeen candidates hoping to challenge Trump have qualified for the Democratic ballot, including all of the leading candidates who are competing in Iowa, New Hampshire and other states with earlier contests.

Republican primary ballots will go to voters affiliated as Republicans as well as unaffiliated voters. Six candidates, including Trump, have qualified for the Republican ballot.

Unaffiliated voters who haven’t notified their county’s clerk of a ballot preference will receive one for each primary, but they can only vote one ballot.

Cross-party voting typically is rare in primaries. Thus far, said Steve Hurlbert, a spokesperson for the Colorado Secretary of State’s Office, there hasn’t been a noticeable uptick in affiliation changes or withdrawals to indicate a lot of voters are planning to do so for the presidential primaries.