The level editor has many different preset themes based on levels to choose from. Here are the ones currently in the editor and which VFX presets they turn on.
Intimate
An orange background
Rain
A grey shadow around all rows
Vignette
Intimate Simple
An orange background
Simple rain (not selectable)
A grey shadow around all rows
Vignette
Insomniac Day
A grey shadow around all rows
Orange bloom
Vignette
Insomniac Night
A slight white glow around all rows
Blue bloom
Vignette
Matrix
Matrix
A white glow around all rows
Neon Museum
A white glow around all rows
Crosses Straight
A white glow around all rows
Embers (not selectable)
Crosses Falling
A white glow around all rows
Embers (not selectable)
Cubes Falling
A white glow around all rows
Cubes Falling - Nice Blue
A white glow around all rows
Vignette
Oriental Techno
Kaleidoscope
Politician's Rally
A black outline around all rows
Rooftop
Automatically moves rows
Sky
A grey shadow around all rows
Orange bloom
Vignette
Night Sky
A white glow around all rows
Blue bloom
Vignette
Hall of Mirrors
It's complicated. Don't use this theme as it is only here for backwards compatibility, instead use the VFX preset.
Skip to the Hall of Mirrors page to get an explanation of its effects.