I have no net income from my CO rental property on the federal side, but CO doesn't seem to care and is taxing me as if I earned money. Is there a way around this?

You need to be sure you are completing your non-resident state tax return before your resident state return.

To delete your resident state return and reenter it in TurboTax Online please follow these steps:

1. Within your return click on State in the black menu bar on the left
2. Click Continue to get to the Status of your state returns screen 
3. Use the trash can icon for your resident state to delete the return
4. Click Edit for the non-resident return to allocate your income there
5. when the non-resident return is complete, you return to the Status of your state returns screen again
6. Click the Add another State button, add your resident state, and progress through the questions to complete your return.