Logically speaking, there are three primary colors, which can change in countless ways. But green does have many meanings and represents rich ideas. Another important thing is that a good trademark can be remembered by people. No one will remember complicated things. The design of the LOGO must conform to the characteristics of the brand and be simple and easy to remember, so that it can be easily used on its own products (there is a cost to make the LOGO into a physical product, as well as the design), so it is not difficult for these simple colors to become a popular LOGO. Sexy. (White is too common to display on web pages, and black is the same. Think about whether the earliest systems without windows were all about typing letters and inputting commands, such as the screen at the beginning.)