Colo. Rev. Stat. § 13-90-117.5
In lieu of an oath or affirmation, any child who testifies in any proceeding pursuant to section 13-90-106 (1)(b)(II) shall be asked the following: Do you promise to tell the truth?. The court, in its discretion, may accept any indication of assent to this question by the child.
Source: L. 90: Entire section added, p. 985, § 4, effective April 24.