Over the past 3 years I have been obsessivley digging through design systems and their approach to color theming. This comes as a result of me wanting to build a JS library for automatically generating color themes from very minimal inputs (UmbraJS). In this talk I would like to share the insights that I have gained in doing so - explaining how I approach thinking about color tokens, what challenges still exist with calculating accesibility contrasts in colors and why I think color is the most foundational part of any design system.