I've been mentoring students on http://trydesignlab.com/ for a while (until I launched my own course) and it's a great point to start. They have a UX Academy where you learn from the basics to create a fully-functional portfolio site with 3-4 case studies. Source: almost 3 years ago

Atlassian Design System: Atlassian's Design System encompasses a color module encompassing primary, secondary, and functional colors, along with an extended palette for shades and tints. The system provides comprehensive guidelines for effective color usage and emphasizes accessibility. - Source: dev.to / 9 months ago

Atlassian design system: https://atlassian.design/. Source: about 1 year ago

Regarding discoverability, you could build a directory with documentation. Similarly to how design systems are documented, e.g: https://atlassian.design/ But if you really want to share them you'll probably need to evangelize it somehow. Source: about 1 year ago

Step 5: Study design system Atlassian design system Primer design system Spectrum, Adobe’s design system Carbon design system. - Source: dev.to / over 1 year ago

Have you checked out https://atlassian.design/ and https://www.atlassian.com/team-playbook? They're pretty good. Source: over 1 year ago