This story originally appeared on PEOPLE.
On Monday, the black actress took to Instagram to slam a photo agency for misidentifying her for fellow black costar, Hinton, 34, after McCreary attended an Emmys party on Friday.
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"LONG READ. I had the best time at the EW party Friday night, getting hyped for the Emmy's, our upcoming Grey's season premiere this Thursday, and celebrating artists who have created visionary, groundbreaking television for us to enjoy this fall," her post began. "Saturday morning, I searched the internet for my carpet photos so I could post them here and give credit to my glam team who straight KILLT it, but I could find none."
"Finally, with a sinking feeling, I searched for the name of my castmate, Jerrika Hinton, who did not even attend the event. Lo and behold, there I was!!" the message continued. "How did I know I would find them there? Well, because this isn't the first time this has happened."
McCreary, 35, explained that she was bothered by "the careless conflation of two black actresses with curly hair on the same TV show."
She continued, "I wonder, does this happen when there are two blonde women in the same cast? When there are two dark-haired white dudes with blue eyes? Maybe it does. But I'll tell you what – to constantly wonder whether I'm facing a micro-aggression I should call someone out on, or a harmless mistake I should let slide, is a real energy drain. The noise of the internal debate with myself is, as Maggie Pierce said last season, 'like a low buzz.' Such is life for people in marginalized groups – including those of us with many privileges – noisy and draining."
McCreary did reveal that the agency and a handful of outlets corrected the error, but she needed to speak up about the "unconscious biases."
"This morning, I discovered that Getty Images and some other outlets have corrected the error, and I am appreciative. So I'll just take this as an opportunity to do a quick PSA – Check your unconscious biases today," she wrote. "We all have them. Managing them takes discipline, vigilance, and self-awareness, and you can practice it anytime. Why not do it today?"
McCreary closed out her post by writing, "And in the words of my castmate, I simply ask the folks who are in the business of identifying distinct and unique human beings to Do Better."