Trellis is a good resource for searching state court trial dockets, including Colorado. Trellis covers 45 states. Docket pages are searchable from 2005-2025. Documents are searchable if they are attached to the docket. At the minimum,complaints/petitions should be searchable for the past few years for all 45 states.
Read about searching in Trellis here and watch Trellis search video tutorials here.
The Colorado Supreme Court Library manages the state's remote public access terminal (RPAT). The database has very limited search functionality, but you can search by party name or docket number. Because Trellis has state trial court dockets, you would probably only use RPAT to find filings for Colorado Court of Appeals and Supreme Court cases. You can request an RPAT account by emailing the state Supreme Court library at library@judicial.state.co.us. You will need to submit a form for the initial account, and you will need to resubmit/reactivate the account every 90 days.