C.R.S. § 8-5-102

(1) An employer shall not discriminate between employees on the basis of sex, or on the basis of sex in combination with another protected status as described in section 24-34-402 (1)(a), by paying an employee of one sex a wage rate less than the rate paid to an employee of a different sex for substantially similar work, regardless of job title, based on a composite of skill; effort, which may include consideration of shift work; and responsibility, except where the employer demonstrates each of the following: (a) That the wage rate differential is based on: (I) A seniority system; (II) A merit system; (III) A system that measures earnings by quantity or quality of production; (IV) The geographic location where the work is performed; (V) Education, training, or experience to the extent that they are reasonably related to the work in question; or (VI) Travel, if the travel is a regular and necessary condition of the work performed; (b) That each factor relied on in subsection (1)(a) of this section is applied reasonably; (c) That each factor relied on in subsection (1)(a) of this section accounts for the entire wage rate differential; and (d) That prior wage rate history was not relied on to justify a disparity in current wage rates. (2) An employer shall not: (a) Seek the wage rate history of a prospective employee or rely on the wage rate history of a prospective employee to determine a wage rate; (b) Discriminate or retaliate against a prospective employee for failing to disclose the prospective employee’s wage rate history; (c) Discharge, or in any manner discriminate or retaliate against, an employee for invoking this section on behalf of anyone or assisting in the enforcement of this subsection (2); (d) Discharge, discipline, discriminate against, coerce, intimidate, threaten, or interfere with an employee or other person because the employee or person inquired about, disclosed, compared, or otherwise discussed the employee’s wage rate; (e) Prohibit, as a condition of employment, an employee from disclosing the employee’s wage rate; or (f) Require an employee to sign a waiver or other document that: (I) Prohibits the employee from disclosing wage rate information; or (II) Purports to deny the employee the right to disclose the employee’s wage rate information.