What is the appearance of water: uniform or nonuniform?

In science, there are two main types of mixtures: uniform (or homogeneous) and non-uniform (or heterogeneous). Uniform mixtures are mixtures where all of the elements and components have the same characteristics and their composition is uniform; homogeneous mixtures appear the same throughout. Some apt examples of uniform mixtures would be alcohols that are soluble in water, like vodka, pure water, water mixed with salt and sugar, soda, and even blood plasma. Interestingly enough, homogeneous mixtures aren't always liquid, and they can be solids or gases as well, like air.
Heterogeneous mixtures are mixtures where all elements and components have different properties and the composition is non-uniform; they appear to be completely different to the eye, as we can see the various components that make up the mixture. Like uniform mixtures, non-uniform mixtures can be liquids, solids and gases. A typical example of a liquid non-uniform mixture is salad dressing; in fact, everything in nature can be considered a non-uniform mixture if it's composed of different elements that have visibly different properties. So, while pure water will appear uniform, or homogeneous, bodies of water out in nature will likely contain particles and be nonuniform, or heterogeneous, in appearance.