Question

What is the colour of the patches in water?

Answer 1

Water. Water absorbs light, so it is usually black or dark blue. Sediment reflects light and colors the water.

Answer 2

The water is in fact not colorless; even pure water is not colorless, but has a slight blue tint to it, best seen when looking through a long column of water. The blueness in water is not caused by the scattering of light, which is responsible for the sky being blue.