Players can utilize hex codes in Overwatch text chat to type messages in colors, gradients, and even send emotes.

The HSL model stands for Hue, Saturation, and Lightness. In this model, hue is a bit like a base color (red, orange, etc.) while saturation approximates that color’s intensity, and lightness describes ...

Such is the case with CSS3-powered gradients. To create them by hand you have to program transitions manually. The code generated is a long list of colour definitions and declarations.