Pool water color might be the most important design element of your pool. After all, it's the biggest focal point you'll see from inside the house, or when lounging in your backyard.

But there are a lot of variables that come into play when selecting your ideal water color, and if you're not careful, you may end up with a pool that doesn't quite look the way you were expecting.

Why Pool Water Color Matters

Water is a clear, transparent fluid that has no discernable hint of color in it — so why does pool water come in various shades of blue, green, or dark turquoise?

The short answer is that the pool's water color is an illusion. Clean water will always be clear. But there's ways to "tint" it, giving the impression that the pool is filled with colored water.

A common misconception is that the color is due to the reflection of the sky, which is blue. There's some truth in this due to water's reflective qualities, but it's not the only factor. A pool with emerald colored water is reflecting the exact same sky that a light blue pool does.

The truth is, there are multiple factors that determine a pool's water color, and yes… the color matters.

Pools are not only a functional structure, but they also add a therapeutic element to your life. A big part of this element is their visual aesthetic.

Pools can have light aqua water for a tropical feel, or deep green water that looks like an exotic lagoon, bringing your water features to life.

Some pools can even imitate a dark blue lake, with the surrounding environment mirrored on its surface.

When designing your pool area, the water color needs to be considered for aesthetic uniformity – providing color blend or contrast throughout the space.

What Gives Pool Water It's Color?

The sky isn't the only component that makes your pool water a certain color. Keep the following in mind when you're in the design stages.

1. Your Pool Finish

An inground pool is basically a hole in the ground with plumbing and a concrete frame. A pool interior finish needs to be added to it so that water doesn't leak through the porous concrete.

About 75% of your pool water color is determined by the color of your pool's finish.

There are 3 types of pool finishes: plaster, aggregate, and tile.

Plaster is the old school, tried and tested option. It's applied by hand, trowelled to make it smooth, and is the most budget-friendly option.

Plaster can be white, or dyed to any color you'd like. When deciding on a pool plaster color, it's important to understand what the resulting water color will be.

Another finish you can put on your pool is aggregate, which is dyed plaster infused with things like stones, pebbles, and crystals. Aggregate can be polished for a smooth finish, or exposed for an anti-slip feel underfoot.

Their added elements create reflections and sparkle in the water that a traditional plaster finish can't match.

If money is no object, you can finish your pool with tile. They come in various styles (ceramic/porcelain, stone, and glass), endless colors, will make your pool ultra-luxurious, and will potentially last forever.

2. The Size and Depth of Your Pool

For those with a smaller, more shallow pool size, you'll have a hard time getting rich pool water color from it.

Without getting too much into the physics and optics side, shallow water is easier to see through than deep water.

Think about the last time you went to the beach.

When you're on the shore, you can still see the bottom of the ocean when the water barely covers your ankles. Venture out further, and the ocean floor begins to disappear.

Why is it disappearing?

As there's a greater mass of water at that depth there's less light absorption. This creates a dark, opaque look to the water.

Pools that have a shallow end and a deep end will end up with a color gradient in their water. Additionally, large pools will have a richer and darker water color than small pools due to their additional water mass.

3. Your Pool's Exposure to Light

As earlier mentioned, many people think pool water color is due to the reflection of the sky.

But the truth is that it's sunlight, not the sky, that plays a more crucial role.

Full-spectrum light, such as the sun, is made up of various wavelengths: red, yellow, blue, green, violet, and ultraviolet. When sunlight reaches the pool, most of these wavelengths get absorbed by the water.

Blue, however, is the wavelength with the lowest absorption rate. The pool's water stays in the color that isn't absorbed as much – blue.

Also of importance is how the water looks in the absence of light.

When the sun starts to set or a portion of the pool is shaded, the water color becomes darker and opaque. Tropical aqua turns to dark aqua, and all the brilliance you get from direct light on the water will be washed out.

Additionally, if you have an indoor pool, or swim at night, you'll want to find out which artificial lights work best to keep your water color the correct shade.

4. The Scenery Around Your Pool

Water is a highly reflective surface, and because of this your surrounding environment adds its own influence to the water color.

This is one of the most common (and frustrating) issues with new pool installations.

Many people will look at a pool photo and say, "I want that color!" So, the pool gets designed with the appropriately dyed finish, but the final product sometimes ends up looking slightly off.

Maybe the water is the wrong shade of blue, or has too much green in it because (as you're quickly finding out) the earthy tones of your backyard are easily reflected.

It's very hard to plan for how every single element in the surrounding environment will influence pool water color.

This is because there's so many of them – from grass and vegetation size and color, to pool deck size and color, patio furniture, surrounding buildings, or windows that are constantly reflecting light.

The good news is that in most cases, the water color will be pretty close (if not identical) to the look you want, as most builders have enough experience to know what things may affect the water color.

5. Your Pools Water Chemistry

A swimming pool uses a host of chemicals in its water to keep the pool sanitized.

It's pH level refers to the water's acidity, which must stay balanced at all times. It's a delicate balance that requires you to keep a close eye on it, as many things can cause it to fluctuate – rain, temperature shifts, airborne contaminants, and even swimmers themselves.

If the ph level does deviate from a balanced state, the water will either become acidic or alkaline, both of which you don't want happening.

When the pool becomes alkaline, the water turns cloudy because the high pH level leads to improperly dissolved calcium.

Alkaline pools are also a breeding ground for algae blooms, which cause your water to turn a lovely shade of toxic waste green.

In contrast, if the pool doesn't have enough chlorine, or too high a level of cyanuric acid (aka pool stabilizer) this will also cause the water to turn that toxic shade.

Additionally, improper circulation (water movement) and filtration can be the culprit of a green pool.

Each day, the filtration system should fully cycle the pool's water to get rid of any contaminants. This is even more vital in the summer months when the temperatures are higher and the pool gets more use.

How to Get The Color You Want

So with all these variables affecting water color, how can you get the look you want?

Here's some advice for creating the following aesthetics:

True Blue

Image by Home Stratosphere

Blue is the most common pool water color, but the range it's available in can be absolutely mind-boggling. Light blue, sky blue, crystal blue, electric blue, tahoe blue, midnight blue – the options can be endless.

To get this water color, the pool finish has to be blue shade. Lighter shades will make the water more transparent, and darker shades will give a deep and rich color.

With blue water, it allows for design versatility, so you can go with either light or dark pool decking for a pristine look.

Aquamarine

Image by Leisure Pools

Aquamarine pools give you the feeling that you're swimming in beautiful turquoise water. While finishes come in plenty of aqua shades, all of them err on the lighter side of the spectrum.

Even though more depth darkens the water color, this is less pronounced in aquamarine pools because of its bright finish, as evidenced in this pool which slopes from right to left.

Another reason for less of this shift in luminosity is because the pool isn't very large or deep. Less water means less light absorption and more reflection, which is why the water sparkles when exposed to the sun.

Aqua Green

Image by Tempool

Aqua green pools are in the same color vein as aquamarine, but their shade is darker, for more of a lagoon look.

The darker finish makes the pool look deeper (even if it's shallow), and gives the water more richness.

Depending on how dark you go, the water will reflect more of the surrounding environment. These pools can be paired with a light deck and coping for contrasted punch, or dark for blending.

Dark Bottom

Image by One Kind Design

Dark pool finishes make the water look opaque (even in sunlight), and come in very dark blues, aquas and even black.

This makes for a visually deep pool with an extremely reflective surface, replicating a natural deep blue lake.

Most dark pools are designed with brighter pool decking for a striking, contrasted effect.

Results May Vary

When you look at a photo of a pool, you have to understand there are elements beyond Photoshop and fancy camera filters that are creating the pool water color you see.

While multiple variables make it hard to guarantee that your pool water will be an exact match, with the right knowledge and execution, most pools will usually still come pretty close.