Created by: michaseel
Inspired by Font-Weights (200, 400, 600...) and the Material Design Color System (https://www.google.com/design/spec/style/color.html#color-color-palette): Use numbers to define different shades of gray. This is much more consistent and extendable than light, lighter, lightest, lightest-light. Because sometimes Designers want just more than 5 shades of gray (or primary colors)