Colo. Rev. Stat. § 13-1-123
When in any civil action pending in any court of record, whether filed as a special statutory proceeding, or otherwise, if for any reason the proceedings could be more expeditiously continued in another county, with the express consent of all parties, the court may order the cause transferred to any other county wherein the court finds the proceedings could be more expeditiously continued. No additional docket fee shall be required. Upon such a transfer being ordered, the clerk shall transfer all files, books, and records of the cause, or, if that is not practicable, he shall make, at the expense of the parties, and send to the clerk of the court to which the cause is transferred a certified copy of all records in the cause which are necessary for the continuation of the proceedings in the court to which such cause is transferred, and the cause shall continue in the court to which it is transferred with the same effect and force as though such cause were originally docketed in such court.
C.R.S. § 13-1-123
For venue and change of venue generally, see C.R.C.P. 98.