Clarified best practices pertaining to Color Palette values (#15006)

* Clarified best practices pertaining to Color Palette values

* Update docs/designers-developers/developers/themes/theme-support.md

@aduth's review

Co-Authored-By: nickylimjj <[email protected]>

* Include explanation for dynamic values

docs/designers-developers/developers/themes/theme-support.md

@@ -114,6 +114,10 @@ add_theme_support( 'editor-color-palette', array(
 ) );
 ```
 
+`name` is a human-readable label (demonstrated above) that appears in the tooltip and provides a meaningful description of the color to users. It is especially important for those who rely on screen readers or would otherwise have difficulty perceiving the color. `slug` is a unique identifier for the color and is used to generate the CSS classes used by the Gutenberg color palette. `color` is the hexadecimal code to specify the color.
+
+Some colors change dynamically — such as "Primary" and "Secondary" color — such as in the Twenty Nineteen theme and cannot be described programmatically. In spite of that, it is still advisable to provide meaningful `name`s for at least the default values when applicable.
+
 The colors will be shown in order on the palette, and there's no limit to how many can be specified.
 
 Themes are responsible for creating the classes that apply the colors in different contexts. Core blocks use "color" and "background-color" contexts. So to correctly apply "strong magenta" to all contexts of core blocks a theme should implement the following classes: