Pot may be legal in Colorado, but you can still be fired for using it.

Brandon Coats, a quadriplegic medical marijuana patient who was fired by the Dish Network after failing a drug test more than four years ago, says he still can't find steady work because employers are wary of his off-duty smoking.

In a case being closely watched around the country, Colorado's Supreme Court on Tuesday will hear arguments in Coats' case, which could have big implications for pot smokers in the first state to legalize recreational sales of the drug. The case highlights the clash between state laws that are increasingly accepting of marijuana use and employers' drug-free policies that won't tolerate it.

"Attitudes are changing toward marijuana. Laws are going to have to change, too," Coats told The Associated Press. "I'd like for this to enable people like me to find employment without being looked down upon."

Coats, 35, was paralyzed in a car crash as a teenager and has been a medical marijuana patient since 2009, when, after a doctor's urging, he discovered that pot helped calm violent muscle spasms that were making it difficult to work.

Coats, who worked for three years as a telephone operator with Dish, was fired in 2010 for failing a random company drug test. He said he told his supervisors in advance that he probably would fail the test.

He said he was never high at work, and Dish did not allege he was ever impaired on the job. But pot's intoxicating chemical, THC, can stay in the system for weeks.

Coats is making his argument under a state law intended to protect cigarette smokers from being fired for legal behavior off the clock.

But the company argues that because pot remains illegal at the federal level, medical marijuana isn't covered by the state law. A trial court judge and Colorado's appeals court agreed.

A patchwork of laws across the country and the conflict between state and federal laws has left the issue unclear. Twenty-three states and Washington, D.C., allow medical marijuana, but courts have ruled against employees who say their pot use is protected. Colorado and Washington state also now allow recreational sales, though court cases so far have involved medical patients.

Colorado's constitution specifically says that employers don't have to amend their policies to accommodate employees' marijuana use. But Arizona law, for example, says workers can't be punished for lawfully using medical marijuana unless it would jeopardize an employer's federal contract.