Slack Themes - Make your Slack pretty with custom themes
Google Cloud Repositories - GitHub alternative by Google
Rainglow Color Themes - 320+ color themes for a variety of editors and software.
AWS Amplify - JavaScript library for app development using cloud services
Branded Slack Themes - 1,000+ themes to customize your Slack
VanillaList - Repository of handpicked best vanilla JavaScript plugins and resources to save time as a developer and create high-performance web apps.