Why are many electronic parts and circuit boards green?

There are several real reasons:
1. Most importantly, in the UV exposure process of solder resist layer, the pigment needs to not absorb ultraviolet light as much as possible. The selection of pigments with stable high temperature performance, good affinity with solvents and meeting various electrical specifications is limited. Green, blue and red solder resist have good UV transmittance, which can achieve high exposure accuracy, such as 2mil solder bridge. Black, white and yellow are poor, generally only 3mil.
2. Need for line inspection. Black and white solder resists are the most unfriendly, and it is difficult to see the wiring. Red and blue are slightly better, and the clearest ones are yellow and green.
On the picture, you can see the difference intuitively.
2. Need for line inspection. Black and white solder resists are the most unfriendly, and it is difficult to see the wiring. Red and blue are slightly better, and the clearest ones are yellow and green.