Pure water is colorless, odorless and tasteless.
The blue ocean color you see is due to reflections from the sky. Due to the chemical properties of water, pure water with nothing dissolved in it is rarely found in nature. Rivers often look brown or green due to the sand or mud in them. Water is a scarce and precious resource. Unfortunately for us, most of this is salt water in the oceans and seas and much of the rest is frozen on mountains and polar ice caps.