On Thursday, more than 2,000 Starbucks baristas protested the company’s new dress code. Starbucks put new limits starting Monday on what its baristas can wear under their green aprons. The dress code requires employees to wear a solid black shirt, khaki or blue and black denim bottoms. Under the previous dress code, baristas could wear a broader range of colors and patterned shirts. Since the new rules, Starbucks has argued that it would make the green aprons stand out and create a sense of familiarity for customers.

“Starbucks has lost its way. Instead of listening to baristas who make the Starbucks experience what it is, they are focused on the wrong things, like implementing a restrictive dress code,” said Paige Summers, a Starbucks shift supervisor from Hanover, Maryland. Others have also criticized the company for selling styles of Starbucks-branded clothing that employees are no longer allowed to wear to work on an internal website. On Wednesday, the Starbucks Union had a total of 1,000 workers stage a walkout at 75 U.S. stores. “It would be more productive if the union would put the same effort into coming back to the table that they’re putting into protesting by wearing black shirts to work,” argued Starbucks in a statement.

The Starbucks Workers United said this week that it filed a complaint with the National Labor Relations Board alleging Starbucks’ failure to bargain over the new dress code.