Everything now, solid or liquid, is made up of small particles. When light strikes these particles, they absorb some of the light's hues while rejecting others. Water seems colorless because it reflects all colors simultaneously. Color comes from the way that different wavelengths of light are reflected or absorbed when light hits any object.
If you were to zoom in on a droplet of water under a microscope, you would see that it is made up of even smaller particles called molecules. These molecules can either be polar (with positive and negative ends) or non-polar (without a positive or negative end). When light hits a molecule, it may or may not reflect the light; if it does not reflect the light, it will instead absorb it. Polar molecules tend to be more reflective than non-polar ones because there is more surface area for light to interact with. This is why white paint is usually used as canvas for painting - the light waves are reflected by the canvas' surface and don't get absorbed.
When light waves strike a molecule, they can change its vibrational state. Vibrational states are like the musical notes that make up a song. The note "A" has a certain frequency and can only be played on an acoustic guitar. The note "C" has another frequency and can be played on a piano.
If a body only reflects a few hues of the visible spectrum while absorbing the rest, it appears in that reflected color. Water's tri-atomic (2 hydrogen atoms and one oxygen atom) structure does not absorb any colors from the visible spectrum of light. As a result, water looks colorless. 1835: Joseph Louis Lagrange shows that the motion of the planets can be used to make accurate predictions about when and where rain will fall. The gravitational pull of the moon causes Earth's oceans to swirl like a giant liquid clock, making tides that rise and fall twice a day. This effect was first noticed by Lagrange using data collected by Napoleon's army during his Egyptian campaign.
1838: William Hyde Wollaston discovers that the blue component of turquoise is actually silver. He makes this discovery by analyzing samples of ancient Turkish coins that he has found in his garden at his home in England. Because silver is white, this analysis allows him to see what kind of stone these ancient coins are made of even though they are covered with corrosion due to exposure to air and soil. Modern scientists use a similar method to analyze the makeup of rocks.
1841: Samuel Pierpoint Langley builds the world's first successful airplane. It is a large glider with two wooden wings that fold back against the body when not in use. Powered by a horse carriage engine, the plane can fly for several minutes before crashing into the ground.
This is the color that is reflected back from the particles and reaches our sight. Water is colorless and transparent because everything except a very little amount of blue (for pure water) is reflected back. It seems transparent because you can see through it.
Pure water is called "distilled water" or "drinking water". Distilled water is water after its hardness has been reduced by passing it through a filter made of glass or plastic. The word "distillation" comes from the process of separating alcohol from water by heating them separately to create a vapor that will condense on cooling. Alcohol evaporates at lower temperatures than water so more alcohol will remain in the still after it has dried out.
Alcohol is used as a solvent for paints, lacquers, and other substances that dissolve in it but not in water. Paint thinners are also called solvents because they help paint dry faster. They work by breaking down some of the chemicals that make up paint formulas, reducing their viscosity (thickness), so they can be mixed with water and sprayed like a liquid. The thinner also contains additives such as sulfur compounds that evaporate during drying leaving small pores in the paint film. These pores allow air and any subsequent coats of paint to seal out any moisture which prevents mold growth and deterioration.
Water has an index of refraction that falls between between that of air and that of many solid materials. This decreases reflection, enabling more light to reach the dye and be absorbed. The substance appears darker. As with any pigment, less color will be absorbed if the water is clear instead of cloudy.