Hi, we know that sea is blue and sky is also blue but why sky is blue? is the sky rally blue or are there anything make it look blue? the answer is yes the light which is coming from the sun it has several colors we can find them by disintegrating the waves. For example the red light has the longest wave. When the light come from the sun it collision with atmosphere and it causes the light disintegrate by atmosphere so that a special range and wave of light we see, this wave interpret blue by our brain. So that sky like blue.