Colo. Rev. Stat. § 15-1-304
In acquiring, investing, reinvesting, exchanging, retaining, selling, and managing property for the benefit of others, fiduciaries shall be required to have in mind the responsibilities which are attached to such offices and the size, nature, and needs of the estates entrusted to their care and shall exercise the judgment and care, under the circumstances then prevailing, which men of prudence, discretion, and intelligence exercise in the management of the property of another, not in regard to speculation but in regard to the permanent disposition of funds, considering the probable income as well as the probable safety of capital. Within the limitations of the foregoing standard, fiduciaries are authorized to acquire and retain every kind of property, real, personal, and mixed, and every kind of investment, specifically including, but not by way of limitation, bonds, debentures, and other corporate obligations, stocks, preferred or common, securities of any open-end or closed-end management type investment company or investment trust, and participations in common trust funds, which men of prudence, discretion, and intelligence would acquire or retain for the account of another.
C.R.S. § 15-1-304
For investments by custodians under the "Colorado Uniform Transfers to Minors Act", see § 11-50-113; for legal investments, see part 6 of article 75 of title 24; for investments of police and fire pension funds, see § 31-31-302.