Colo. Rev. Stat. § 31-12-303
No order shall be made by any district court requiring the submission of the question of dissolution and annexation to any election held pursuant to this part 3 until the city existing under a special charter to which it is proposed that such annexation be made has consented to such annexation by ordinance duly passed and published. In case of the annexation of any city or town to any city existing under a special charter, as provided in section 31-12-301, neither the indebtedness of the city or town so annexed nor that of the city to which the same shall be annexed shall become a common indebtedness. Such indebtedness shall be paid by general taxation upon all the taxable property within the city or town in and by which the indebtedness was created.
C.R.S. § 31-12-303
This section is similar to former § 31-8-210 as it existed prior to 1975.