C.R.S. § 7-62-301

(1) After the filing of a limited partnership’s original certificate of limited partnership, a person may be admitted as an additional limited partner: (a) In the case of a person acquiring a partnership interest directly from the limited partnership, upon compliance with the partnership agreement or, if the partnership agreement does not so provide, upon the written consent of all partners; (b) In the case of an assignee of a partnership interest of a partner who has the power, as provided in section 7-62-704 , to grant the assignee the right to become a limited partner, upon the exercise of that power and compliance with any conditions limiting the grant or exercise of the power; and (c) Either upon formation of the limited partnership or thereafter without making a contribution or being obligated to make a contribution to the limited partnership or acquiring a partnership interest, if in either case such admission is pursuant to a written partnership agreement or other writing confirming the admission. (2) A person becomes a limited partner on the later of: (a) The date the original certificate of limited partnership is filed in the records of the secretary of state; and (b) The date reflected in the records of the limited partnership as the date that person becomes a limited partner.