Colorado Code
Part 1 - Composition and Selection of the Jury
§ 16-10-106. Incapacity of Juror

Where a jury of twelve has been sworn to try the case, and any juror by reason of illness or other cause becomes unable to continue until a verdict is reached, the court may excuse such juror. If no alternate juror is available to replace the juror, the parties at any time before verdict may stipulate in writing with court approval that the jury shall consist of any number less than twelve, and the jurors thus remaining shall proceed to try the case and determine the issues unless discharged by the court for inability to reach a verdict.
Source: L. 72: R&RE, p. 237, § 1. C.R.S. 1963: § 39-10-106.