Employment Law Questions? Ask an Employment Lawyer.
Colorado law controls if you are employed "in" Colorado. This is the same whether or not the issue is payroll tax, unemployment insurance, or any other employment-related issue. The law of the jurisdiction in which the employee is substantially employed controls the employee's rights.
If your rights are violated, you can file a complaint at this link.
I hope I've answered your question. Please let me know if you require further clarification. And, please provide a positive feedback rating for my answer -- otherwise, I receive nothing for my efforts in your behalf.
Thanks again for using Justanswer!