Colo. Rev. Stat. § 12-10-208
(2) If a broker has no registered agent registered in this state, the registered agent is not located under its registered agent name at its registered agent address, or the registered agent cannot with reasonable diligence be served, the broker may be served by registered mail or by certified mail, return receipt requested, addressed to the entity at its principal address. Service is perfected under this subsection (2) at the earliest of:
Source: L. 2019: Entire title R&RE with relocations, (HB 19-1172), ch. 136, p. 624, § 1, effective October 1.
Editor's note: This section is similar to former § 12-61-107 as it existed prior to 2019.