Safe colors or, in other words, a web palette were created to harmonize browsers. Previously, when computers and monitors could not display the required number of colors, the developers were very worried about the discrepancy. They worried that their pages would look differently in different browsers and monitors. Older output devices limited developer activity. Therefore, for the safety and security of the original appearance of web pages, web colors were invented.
Creature
As you know, html and css use several methods to determine the color value. Most web developers use special RGB codes that indicate an individual hue number. For example, such an entry: “# 223366” means that 22 - red, 33 - green and 66 - blue should be taken. The latter value is in a predominant amount. And if you mix in such proportions of paint, you get a dark blue color. RGB is an acronym for the English words Red, Green, and Blue. And it was these colors that were chosen for the additive color model, with which the synthesis of paints takes place. Some suggest that html safe colors were assigned at random. But this is not so. The choice was made using a dry mathematical calculation. Only those values that were divided by 3 and which have a pair of identical digits were selected. For example: "# 663366" or "# cc0099" (where c means 13). And colors like "# ff66d6" or "# 9999AA" are no longer safe colors because they violate the basic rules. If the monitor met a hue unknown to him, then he tried to replace it or create a new paint. Most often, a dithering system was used in which colors were mixed to create another. Sometimes this method helped to avoid the irreversible consequences of incorrect display, but there were cases when the picture of the site completely changed. That is why a separate color palette was created , which had full coordination with devices and browsers of that time.
Using
As you probably already understood, safe colors for the site look very poor, since there is not a wide variety of shades and overflows. But in the days of using old monitors, such a palette was the only way out to get the same image display on different devices. Now there is no need to use safe colors, because almost every Internet user has modern equipment that easily produces all the famous colors. Sites look very poor if you use only a web palette. Some image editors (such as Adobe Photoshop) still leave the option of selecting only safe colors. But progress does not stand still, and every year in the field of programming something new appears.
Conclusion
Use safe colors today does not make sense. Almost all old monitors are replaced with new ones. Therefore, safe colors already go down in history and will soon completely disappear from all programs and web pages.