Yes, and "I didn't feel like selling something" is not based on race, color, religion, or national origin. I would add sexual orientation to that list as well. So you have nothing.
To me you're just determined to close your eyes. Maybe this will help...say you were born mute, but every time you see a black man you spit at him, grimace and raise a middle finger. You don't respond the same to white men, Native Americans, people of Latin origin, etc.
But a black man walks by and you spit and grimace and gesture emphatically.
Are we left, by virtue of your inability to speak, to only wonder if you have a specific problem with blacks?
Of course not.
Conduct can be speech. Habit can be used as evidence. And the law doesn't say that you must admit a blessed thing, only calls for the thing alleged to be demonstrated subject to the level of proof.