What you described is basically a casual labor situation and I think you’ll find that in fact they are employees for worker’s comp purposes. Colorado’s worker’s comp law is very expansive regarding who all are considered employees and most cases of casual labor like this are indeed employees. Indeed Colorado’s worker’s comp statute tells you this because it provides an express exception from worker’s comp coverage for casual workers if the business or employer does not already employ workers subject to worker’s comp and certain other conditions are met. The problem here is that you evidently do already employ other workers who are covered by worker’s comp and thus this exception would not seem to help you. Specifically Colo. Rev. Stat. § 8-40-302(3) states:
(3) Articles 40 to 47 of this title are not intended to apply to employers of casual farm and ranch labor or employers of persons who do casual maintenance, repair, remodeling, yard, lawn, tree, or shrub planting or trimming, or similar work about the place of business, trade, or profession of the employer if such employers have no other employees subject to said articles 40 to 47, if such employments are casual and are not within the course of the trade, business, or profession of said employers, if the amounts expended for wages paid by the employers to casual persons employed to do maintenance, repair, remodeling, yard, lawn, tree, or shrub planting or trimming, or similar work about the place of business, trade, or profession of the employer do not exceed the sum of two thousand dollars for any calendar year, and if the amounts expended for wages by the employer of casual farm and ranch labor do not exceed the sum of two thousand dollars for any calendar year.
(Bolding added.) The part that I bolded is what tells you that this exception applies only if you have no other employees subject to the worker compensation law. I suggest you discuss this with a worker’s comp attorney and/or the worker’s comp carrier because this may well be something that needs to be submitted as a worker’s comp claim.