Many different careers are hard to break into. The nursing one is certainly one of them. You have to take challenging courses in college, take part in practicums and pass the National Council Licensure Examination for Registered Nurses (NCLEX-RN) before you can apply for your professional license. Landing a job after all these steps can be hard, especially given the competitive job market.
No one would want to work so hard to land a job in nursing, only to put it at risk, but a criminal conviction may jeopardize your career.
Many professional license holders may understand that the licensing board performs a background check on applicants when they first apply for this labor permit; they're unlikely to ever check up on them again. This isn't the case, though.
The Colorado Board of Nursing performs random background checks on license holders. They could notice it then or when you submit your renewal application. This could result in your file being flagged.
While the licensing board may give you the benefit of the doubt and reach out and ask questions if they notice that you didn't report your conviction, it's unlikely. They could suspend or revoke your license instead. Depending on the situation, the board may simply decide to discipline you for not reporting your conviction. At the same time, a conviction for a crime of moral turpitude such as fraud may motivate them to revoke your license. They may require you to complete treatment for substance abuse if the conviction is associated with that.
Your best-case scenario is if you can aggressively defend yourself against the charges you face and receive an acquittal. If you end up facing sentencing, you may face more than jail time and have to pay fines. You may also end up losing your career.