You must have noticed that the color of the solar panels is generally blue. The function of the solar panel is to absorb the sunlight and convert it into the electric current. The more it absorbs the sunlight, the more it produces the electric current.
This is a fact that the black color absorbs the maximum light, you will feel more heat wearing a black T-shirt than wearing a red one. Despite this we find that the blue colored solar panels are more prevalent than the black ones
The silicon is generally used in making the solar panels. It is a non-metallic element with properties of absorbing most of the visible light and produce electricity.
There are two kinds of the solar panels:
Out of total panels installed, almost 90% of them are poly-crystalline. Hence, we see blue colored solar panels around us. Well there is valid reasons for this, because it is relatively easier and cheaper to commercially produce them.
The manufacturing process along with coating of the anti-reflective layer give blue color to the poly-crystalline solar panels.