This is a dark theme for PgAdmin query editor. It's based on Obsidian by Morinar:

[ctlSQLBox]
MarginBackgroundColour=rgb(221, 221, 221)
ColourCaret=rgb(191, 191, 191)
Colour1=rgb(126, 141, 148)
Colour2=rgb(126, 141, 148)
Colour3=rgb(224, 226, 228)
Colour4=rgb(255, 205, 34)
# syntax color
Colour5=rgb(102, 139, 176)
Colour6=rgb(236, 118, 0)
Colour7=rgb(236, 118, 0)
Colour10=rgb(147, 199, 99)
Colour11=rgb(147, 199, 99)
Just add this section to $HOME/.pgadmin3 and start PgAdmin.