Colo. Rev. Stat. § 10-3-225
Domestic insurance companies may invest in equipment trust obligations or certificates which are adequately secured, or in other adequately secured instruments evidencing an interest in transportation equipment wholly or in part within the United States, and the right to receive determined portions of rental, purchase, or other fixed obligatory payments for the use or purchase of such transportation equipment; but the aggregate investments by a company which may be admitted assets under this section shall not exceed ten percent of the company's admitted assets, and the investment in the obligations or certificates of or in relation to any one transportation company, which may be admitted assets under this section, shall not exceed two percent of the investing company's admitted assets.
C.R.S. § 10-3-225