In contrast, “blue” pro-government and pro-China businesses are frequent targets for vandalism or boycotts.

At Fu Kee Noodles in Wan Chai, diners slurp wonton under the watchful gaze of a gas mask-wearing Pepe the Frog, which has become a mascot of the pro-democracy movement.

“This is a yellow shop, the boss supports the protesters, so we decided to come,” said a 47-year-old advertising employee calling himself Gilbert.

“The most important thing in Hong Kong now is that we need to help each other, especially when the government does not help us.”

Posters and post-it notes with pro-democracy messages cover the wall by the cashier.

Owner Kwong Chun-hin, 30, told AFP he hopes the yellow-blue tagging will become a trend “because this is good for us. I mean not just my shop, I mean all shops”.