CO Mechanics Lien Law

In Colorado, a mechanics lien expires within 6 months of the date the project was completed, or labor or materials were last furnished to the project; whichever is later. The lien claimant must file an action to enforce their lien claim before the deadline or the claim expires and is no longer enforceable.

My explaination: The mechanics lien is a temporary lien, according to above, the contractor has to file an action in court to enforce the lien OR it will expire.  Look at your lien closely and report back what exactly it says. 

Yes, Colorado is a “full price lien state”. However, if the project is a owner-occupied, single-family residence, the lien will be limited to the unpaid balance to the general contractor.

My explaination: your parents as home owner should not be liable if they paid the general contractor in full. 

You parents should just wait for the lien to expire OR recieve an action to enforce the lien, at that time they can respond in court and have the lien removed.