Looking at the sea, it is often found that the sea is blue and green. However, when you pick up the sea water, you can only see that it is transparent and colorless like the water of the past. It turns out that the sea water itself is not much different from the water we come into contact with every day, and it is also transparent. The green color we see is actually a phenomenon produced by the ability of seawater to absorb light. Only green light can be absorbed by the sea water and thus reflected; when the sea water is deeper, the green light is also absorbed, and the sea water appears blue.