What does Huang Majia's leader mean by saying this?

The yellow vest has two meanings: one refers to the yellow vest courier. One refers to the "yellow vest" movement in France.

There are white vests (equivalent to passers-by), green vests (temporary guests), green vests (long-term guests), blue vests (blue horse means you are a member of this guild), yellow vests (guild management), red vests (channel manager), pink vests (channel management, hehe is equivalent to blue horse) and orange vests (also an administrator, equivalent to vice president of the guild).

The specific situation depends on the environment and tone of your leadership at that time. Maybe it's a personal opinion, maybe it's a description of things to express his central idea, maybe it's just humor.