green, blue

青 depicts a well surrounded by grass, well has water , so the grass around it is always green. In the past, 青 was used to represent the colour of green and blue, but such two meanings had been replaced by 綠 and 藍, now 青 mainly means the colour of light green. On the other hand, when a tree is densely covered by green leaves, it looks dark, so 青 is also used to describe something in dark colour, like hair and eyes.