This is a theme for Pi. Two variants are available:
electron-highlighter.json— the dark theme (Electron Highlighter)electron-highlighter-day.json— the light theme (Electron Highlighter Day)
To install, copy the file(s) you want into ~/.pi/agent/themes. Then when you open Pi, type /settings, go down to the Theme section, and choose Electron Highlighter or Electron Highlighter Day.