Colo. Rev. Stat. § 13-90.5-106
An application to the court for a protective order or to enforce, quash, or modify a subpoena issued by a clerk of court under section 13-90.5-103 must comply with the rules or statutes of this state and be submitted to the district court for the county in which discovery is to be conducted.
C.R.S. § 13-90.5-106
OFFICIAL COMMENT
The act requires that any application to the court for a protective order, or to enforce, quash, or modify a subpoena, or for any other dispute relating to discovery under this Act, must comply with the law of the discovery state. Those laws include the discovery state's procedural, evidentiary, and conflict of laws rules. Again, the discovery state has a significant interest in protecting its residents who become non ‐party witnesses in an action pending in a foreign jurisdiction from any unreasonable or unduly burdensome discovery requests, and this is easily accomplished by requiring that any discovery motions must be decided under the laws of the discovery state. This protects the deponent by requiring that all applications to the court that directly affect the deponent must be made in the discovery state.
The term "modify" a subpoena means to alter the terms of a subpoena, such as the date, time, or location of a deposition.
Evidentiary issues that may arise, such as objections based on grounds such as relevance or privilege, are best decided in the discovery state under the laws of the discovery state (including its conflict of laws principles).
Nothing in this act limits any party from applying for appropriate relief in the trial state. Applications to the court that affect only the parties to the action can be made in the trial state. For example, any party can apply for an order in the trial state to bar the deposition of the out-of-state deponent on grounds of relevance, and that motion would be made and ruled on before the deposition subpoena is ever presented to the clerk of court in the discovery state.
If a party makes or responds to an application to enforce, quash, or modify a subpoena in the discovery state, the lawyer making or responding to the application must comply with the discovery state's rules governing lawyers appearing in its courts. This act does not change existing state rules governing out ‐of ‐state lawyers appearing in its courts. (See Model Rule 5.5 and state rules governing the unauthorized practice of law.)