Don't have a choice to refuse the tests in CO apparently. From the police report of the cocksucking asshole drunk driver that hit my son this weekend:
I explained Colorado Express Consent Law to Joshua. Joshua refused to complete either a blood or breath test. I asked Joshua if he understood that, by refusing to take either test, his driver's license would be revoked for a period of at least one year. Joshua replied that he understood.
I've done a field sobriety test before (smell of alcohol from passengers), and they are a bitch.