• Zenithdecker
  A mashup of Maggie's "Leyendecker" theme and Azlen Elza's "Zenith" theme

• Leyendecker (light theme)

  

• Night Owlish (dark theme)

  

Create a new page called roam/css, and create a code block, set the language to css, then paste your chosen theme's CSS code in there. Tada!