How to make a custom color palette, used to control the color of the material ball
You can make a custom color palette by setting up a color-picker UI element with, jscolor, a JavaScript Library for creating and displaying an assortment of colors:
JS Color - Examples
PlayCanvas Demo
I also forgot to mention that the Input HTML element also has a color-palette selection function that you can use to select color(s) that can be later received through JavaScript:
<input type="color">