The wavelengths that excite the hydrogen-oxygen bonds in water exist mainly in the infrared and in the ultraviolet. We just happen not to be able to see those frequencies.

Why is water not white then? Because it is a substance that does not have any changes in its properties all of the way through it (e.g. index of refraction, etc.).

Individual quartz sand grains are clear, but because when you look at sand, you see light scattered through them, it looks white. A solid block of the same material, like a glass window, is clear. Likewise, a cloud, which is made up of water droplets, scatters light off of the surface of the droplets, and appears white (or gray, if you are looking through it).