Green is the most common, there are black, red, blue, yellow
Color and quality are irrelevant, just a kind of personalized performance.
The PCB board mainly considers the material and thickness, and rarely considers the color. What you said should be the color of solder mask ink! Solder resist inks are available in white, yellow, black, red, and blue, as well as a transparent ink. The most commonly used is the green ink. There are differences in solder resist inks used according to the accuracy requirements of the board. . .