How do web programmers manipulate colors usings numbers and mathmatics?

Answer 1

When you are writing the web app or web page, you have options in most cases on how to describe the colors you want your elements to be. In some cases you may want to write the name of a color in English, such as "green" . But behind these names is an actual number value. You may have heard of RGB, or HEX, or HSL, these are Red Green Blue; Hexidecimal; and Hue Saturation Luminance. All of these are color systems using numbers to represent colors (hexidecimal uses numbers and letters but they're still numbers - another question).

For instance, in HSL: the first number is between 1-360 and represents the hue of the color. The second represents how much of the color is present relative to gray pixels. Finally luminosity controls how bright or dark the color looks. Alter these numbers in your code using math to change the color. If blue is H240, then you could program it to change that value by adding or subtracting from that H value and it would change colors. Or you could subtract from L until it went black to kind of fade out.

Since these are all numbered color reference systems, similar methods would work with HEX and RGB as well.