Editora 0.10.0. Archived, so links from that release keep working. Read the 0.18.5 page →
Theme: Set Editor Theme…
theme.setEditorTheme Pick the editor syntax color theme.
How to run it
Open the command palette (M-x in the Emacs keymap) and search for Theme: Set Editor Theme…, then press Enter. It has no default keybinding, but you can bind one in Settings → Keymaps.