Federal law protects Americans from being discriminated against in public places like retail stores on the basis of disability and “race, color, religion or national origin.” Many states go further.
Colorado is one of about 20 states, along with the District of Columbia, that have laws explicitly protecting people from being refused services or otherwise discriminated against in public because of their sexual orientation or gender identity.
Additionally, several states interpret existing laws against sex discrimination to apply to bias relating to sexual orientation and gender identity, even though they do not have laws explicitly forbidding such discrimination.
In states that do not offer protections to gay and transgender people on those grounds, municipal laws cover many residents.