The colour of swimming-pool water

The colour of the water in a swimming-pool is one of the most fascinating aspects of outdoor design.
It depends not on the water itself, which is transparent, but on the interaction between materials, light and depths. Every design choice helps to create a specific mood: bright and crystalline, natural and relaxing or intense and dramatic.

An understanding of how the colour we see is generated helps us to choose the right lining and achieve exactly the effect we’re looking for, reinforcing the identity of the pool and the entire space around it.

What determines the colour of the water in a swimming-pool?

The colour of the lining

The lining is the factor with the most influence over the colour of the water. Porcelain stoneware tiles create the base colour from which light will be reflected.

Pale colours → bright, transparent, sparkling water
Medium colours → more substantial, balanced shades of blue
Dark colours → depth, elegance and a mirror effect

The finish also plays an important role: smooth surfaces are brighter, while textured finishes spread the light more naturally.

The depth of the pool

Variations in the water’s depth naturally affect the colour we see:

In shallower zones the water looks lighter
In deeper zones the shade also acquires greater depth and substance

This gradual change in intensity creates an attractive effect that enables full appreciation of the pool’s shape and volumes..

Natural light

Sunlight creates continuous variations in the course of the day:

Morning → pale, delicate shades
Midday → the brightest sparkle
Dusk → warmer, deeper hues

The pool’s exposure (North/South-facing) and the local climate also influence the water’s perceived colour.

The surrounding environment

Water constantly reflects everything around it. This makes the context a fundamental design factor.

Vegetation and trees: the source of subtle green tones.
Sky: on clear days it provides a stronger blue; on cloudy days or when the sun is low in the sky the colours are more delicate and warmer.
Paving and architecture: light-coloured materials enhance the water’s brightness, while dark shades emphasise its depth.
Areas of shade: they create contrasts and variations in colour that change in the course of the day.

It’s this constant dialogue with the environment that makes every outdoor pool unique.

Water colour and temperature

The choice of colour affects not only the pool’s appearance but also its level of thermal comfort.
The darkest linings, such as dark greys, anthracites or blacks, absorb more sunlight.
This means:

the water will naturally be warmer, with temperature increases of as much as 1–3 °C compared to a pool with a light-coloured lining
less heat loss during the evenings
a more pleasant, warmer feeling when the weather isn’t particularly hot.

Conversely, paler surfaces reflect most of the sunlight, keeping the water cooler and brighter.
So the choice of colour is also a functional consideration, especially important in locations with specific weather conditions or in pools used all year round.

The main water colours and how to achieve them

From transparent water to the most intense shades: every lining generates a different chromatic effect, with the power to transform the pool into a unique, striking outdoor design feature.
The following is a list of the main shades that can be achieved and the materials recommended for creating them.

Light Blue

The water looks crystalline, sparkling and cool.
This is the very natural, bright “swimming-pool blue” we all know, ideal for modern locations and anyone who wants the most transparent effect.

Recommended lining:

Light Green

The water colour created is a very soft, natural green, like that generated by the sand of Caribbean bays.
Perfect for pools surrounded by nature.

Recommended lining:

Intense Blue

The result is a medium blue, deeper than light blue but still sparkling.
It’s one of the most versatile colours because it fits well into contemporary and minimal design schemes.

Recommended lining:

Natural Green

The water acquires an elegant, rich, intense green shade, with a very natural effect.
Ideal in pools set in gardens with lush vegetation or “wild” contexts in the midst of a landscape.

Recommended lining:

Dark Green/Blue

The water looks deep with a mirror-like surface, similar to a natural lake.
It reflects the sky and the surrounding vegetation very strongly, transforming the pool into an immersive feature of the landscape itself.

Recommended lining:

N.B.: The water shades described are purely guideline and are not intended to define benchmark categories.
The variations in shade between tiles within a collection and the choice of more or less intense colours may strengthen or reduce the colour effect actually created in the pool.

Indoor pools

How the colour of the water changes without sunlight

The way the water colour is perceived in indoor pools is very different, because direct sunlight isn’t a factor and there may be only partial daylight, or none at all.
The role of the lining is still fundamental: light, medium or dark shades produce the same basic effects as in outdoor pools, but in a more uniform, predictable way.
The depth also affects the perceived colour, but the differences are less noticeable.

The main variable here is the artificial lighting.

Cold lighting creates bluer, brighter water, warm lighting adds more inviting shades with a touch of gold, and neutral lighting maintains exactly the same colour as the lining, with no change in shade.

What’s more, the lighting’s direction, intensity and diffusion (direct beams or indirect or raking light) shape the reflections and contrasts and thus the overall mood of the pool area.

The water colour in indoor pools is therefore more constant, with the lining and lighting combining to create a precise effect in keeping with the style of the location.