As I contents and mitigation restoration company, am I able to file a valid mechanics lien being that the service may not be seen as a permanent improvement?
It sounds like you're on the right track by thinking about "permanent improvements." Generally, mechanics lien rights are only available to those who have provided some permanent improvement to the property.
By "permanent," we mean that the work has made an improvement or alteration to the property that will be lasting and/or integral to the property for an extended period of time. So, things like maintenance, moving/storing furniture, and other work that doesn't fundamentally alter or affect the immovable property likely won't be considered "permanent" or lead to mechanics lien rights. But, work that fundamentally alters the property for its benefit, like water remediation on the physical structure, might be.
After taking a quick look at Colorado case law, it's not obviously apparent that water remediation would be lienable. However, § 38-22-101(1) of Colorado's mechanics lien statute allows for broad mechanics lien protection by parties who alter or repair property, and the section specifically provides lien rights for those who render professional or skilled services relating to the repair or alteration. So, providing specialized services necessary to repair a building and mitigate water damage would seemingly be lienable.
In any event - a Colorado construction lawyer may be able to help to clear things up here since they'll be better versed in Colorado's lien laws and relevant caselaw. To reach out to an attorney directly, Levelset has a great directory of CO construction lawyers: Top Colorado Construction Lawyers. Additionally, note that a subscription to Levelset's Legal Guard offering could help with the cost: Legal Guard | Put a legal team in your corner.