HSL model: What is and how does it differ from RGB or HEX?

What is the HSL color model and how does it differ from RGB or HEX?

HSL (Hue, Saturation, and Lightness) is a color model and color representation in web development. It is used to describe and manipulate colors more intuitively and perceptually. This makes it especially useful and versatile in applications that involve the selection and execution of colors. With this model, developers can adjust background colors, text, and other visual elements more easily and achieve more impactful visual results.

In graphic design, there are other very common models such as RGB (Red, Green, and Blue), and HEX (Hexadecimal). The following is a brief explanation of each of them:

1. RGB

The RGB color model is based on the combination of three primary colors: red, green, and blue, named above. In this model, each color is specified as a numerical value on a scale from 0 to 225. The combination of these three primary colors allows the creation of millions of different colors.

2. HEX

The HEX color model is similar to the RGB model, but instead of using numeric values from 0 to 255, hexadecimal values from 00 to FF are used to represent each of the three primary colors. Thus, a HEX color is specified as a string of six hexadecimal characters representing the amount of red, green, and blue, respectively. The HEX model is commonly used in web design, as it can be easily specified in HTML and CSS code.

3. HSL

The HSL color model is based on three components:

    • Hue: Refers to the hue or tone of the color, which is measured in degrees and varies from 0° (red) to 360° (red again after one full turn).


    • Saturation: Refers to the saturation or intensity of the color, which is measured as a percentage and ranges from 0% (grey) to 100% (fully saturated color).


    • Lightness: Refers to the lightness or brightness of the color, which is also measured as a percentage and ranges from 0% (black) to 100% (white).


The HSL model allows easier and more accurate manipulation of colours than the RGB model. Especially in terms of adjusting brightness for web accessibility purposes.

Why should you use HSL model in your CSS?

One of the fundamental parameters when working with CSS is the colors. Whether for purely aesthetic reasons or accessibility, the use of color when creating a website is of monumental importance. In the vast majority of cases, the most common is to use one of these three color codes (and their variants with transparencies): RGB/RGBA, HEX, or HSL/HSLA and if you have seen or work with CSS regularly, you will have noticed that the use of RGB and HEX is quite a majority over HSL.

There are several reasons why it may be useful to use the HSL color model in your CSS code:

Accuracy and ease of manipulation

The HSL model allows you to more accurately and easily specify the hue, saturation, and lightness of a color, compared to other color models such as RGB. In addition, you can adjust any of these three properties to change the appearance of the color in a predictable and controlled way. This allows you to better control the color of your design, giving you more agility and precision when creating palettes and combinations.

Reduced complexity

 The HSL model can be easier and more intuitive to understand for developers who have no experience in color theory or manipulating RGB values. Instead of having to adjust the values of three different color components, you simply adjust the HSL values. Only by looking at the first HSL value (the hue) will you know which color you are looking at. Then, if you want to know whether it is a saturated or a low-saturated color, you will have to look at the second value. And finally, you will be able to deduce whether it is a dark or light color with the last value.

Easy accessibility

The HSL model can be very useful in designing for web accessibility, as it allows you to adjust the brightness of a colour while maintaining the same hue and saturation, thanks to a harmony. In this way, you can ensure that elements with different contrast levels are legible and accessible to all people.
In addition, you can create a set of the same shade of secondary colours by modifying only the hue of the primary colour, while maintaining the same brightness and very similar saturation.

Save time and effort by implementing the HSL model

In short, using the HSL color model in your CSS code offers numerous advantages. You will better understand how colors work and you will be able to manipulate them more precisely. You will work in an easier and more accessible way than with other models.

One of the main advantages of the HSL model is that it allows you to adjust the brightness and saturation of the same color to achieve different shades. You can increase or decrease the brightness to create variations of the same color to better suit your design. You can also modify the saturation to achieve more vibrant or more subtle colors according to your needs.

By working with the HSL model in CSS, the hue, saturation, and lightness values are more understandable and expressive than the RGB component values. This allows you to experiment with more harmonious color combinations.

From a design with the same color, you can change the brightness and saturation to achieve different shades.

In short, by using the HSL model you can save time and effort in working with colors when working with design systems. You will gain a deeper understanding of how colors work, and you will improve both your efficiency and the user experience in your design and development projects.

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