5 Reasons Why Pros Use HSL Color Representation in CSS

HSL may seem like just one of many similar color schemes out there but it’s not exactly the case. It certainly belongs to those being the most friendly, intuitive, and even loved. Since its introduction decades ago, HSL has been adopted in a huge number of tools and ways, available for millions of users, and professionals dealing with CSS, making their experience so much better. 

There are many reasons for HSL’s brilliant career, and many advantages it offers. One of them is that reading HSL color is simply very easy – all we need is to know three parameters. But let’s find out in detail why pros use HSL color representation in CSS so willingly.

Some issues that will be discussed in this article on HSL include:

1. HSL in a nutshell. The long-lasting career
2. Deciphering the HSL color code. How to read it right?
3. HSL colors - 5 main advantages of using them
4. Easy as HSL to HEX and HSL to RGB conversion

HSL in a nutshell. The long-lasting career

What is HSL color in detail? Let’s see. 

HSL is an acronym for Hue Saturation Lightness that gives colors a cylindrical-coordinate representation. This kind of color scheme was developed as early as in the year 1938 for television purposes – it was meant to add color encoding to existing monochrome broadcasting.

• Hue – means a given color from the color wheel (representing the color of the rainbow)
• Saturation – stands for intensity or vividness of the particular color
• Lightness – determines a color’s tone, that may be lighter or darker than a regular/default value set in the middle of the scale

To this day, HSL is immensely utilized in color selection tools (or color pickers or choosers) – graphical user interface widgets used to select and adjust color values within graphics software or online. 

Web applications with color selection, image editing software, image viewers, color editors, video editors, and thus maps, or medical images are all where we can find out how HSL works. Photoshop and Final Cut Pro are popular tools utilizing this color scheme. As for web front-end frameworks, HSL coordinates may be used for specifying colors within the CSS 3. Apart from end-user software, HSL is used in computer vision – to analyze and group objects, e.g. based on their features.

Deciphering the HSL color code. How to read it right?

Reading HSL color code is simple and intuitive if we take into account that HSL colors are numerical. 

There are three positions in color code, and those three parameters must always be presented in the same order. These properties of color are:

• Hue – expressed in degrees, as an angle of the color wheel. 0 degrees stands for red, 120 – for green, 240 – for blue, and 360 brings us back to the red.
• Saturation – presented as a percentage where 0% stands for grey, and 100% means the color’s full intensity.
• Lightness – presented as a percentage, with 0% as black, 100% - white, and 50% – the normal lightness value.

A typical representation for any color is hsl(hue, saturation, lightness). 

For example, green is hsl(120, 100%, 50%), and blue – hsl(240, 100%, 50%).

Note that while we use % signs for Saturation and Lightness, degree symbols for Hue are omitted.

As for CSS, HSLA – another color code – may also be used. It is the HSL color scheme enhanced with an additional Alpha component, determining colors’ opacity. It ranges from 0.0 (standing for full transparency) to 1.0 (full opacity).

HSL colors - 5 main advantages of using them

There are many advocates for using HSL color representation. Some of the advantages or benefits of this solution they bring up include:

1. It’s a powerful, flexible yet simple tool offering vast possibilities.
2. It is intuitive (based on the way people see colors) and easy to learn and read fast, following a brief introduction; colors are clearly expressed and the outcome is easy to imagine.
3. It enhances and improves workflow, and makes it more smooth.
4. It can be adopted in a variety of tools, it’s easy to simply jump in and take advantage of it – the HSL function exists in CSS, and may be combined with its other features.
5. It enables creating groups of similar, matching, or working well colors easily.

The latter may be achieved by changing only one position in the color code. For example, we may change the lightness of a given color, changing the last value from 50% (standing for a regular/normal tone) to 75% representing light, or 25% indicating dark. 

Also, as we’re working based on the color circle, we may choose the complementary color, opposed to the basic one by adding 180 degrees to the initial value. Such operations are trivial but make web designers’ lives much easier. They only require subtle changes in code and much less effort than in the case of using pure CSS.

Easy as HSL to HEX and HSL to RGB conversion

Another advantage of HSL color representation is that it can be treated as an alternative to RGB as well as converted into RGB.

Within CSS3, HSL colors are added to RGB ones to complement them. Both HSL and RGB colors are numerical, and HSL to RGB conversion is very easy. All we have to do is use a specific algorithm that translates Hue, Saturation, and Lightness into fractions. Also, we may use one of many online color converters that run on browsers – not only for HSL to RGB but also HSL to HEX conversion. Additionally, some of them include CMYK or HWB, a suggested standard for CSS4.

As we can see, there are many reasons for using the well-established HSL technology in our up-to-date CSS projects. And many reasons why front-end developers more and more often switch to it. Some of them include HSL’s versatility, flexibility, and ease of use as well as being symmetrical to lightness and darkness. As for HSL, CSS pros still tend to prefer RGB or HEX color representation methods but HSL is certainly trending.

And what is your experience with HSL color representation? Do you find this color scheme useful, does it hold good? In which projects can it be used best?