A Neovim port of @rougier's excellent N Λ N O Theme for Emacs: six semantic faces, 15 curated variants, and independent light and dark modes.

Philosophy

Instead of a large syntax rainbow, N Λ N O builds every screen from six semantic faces:

Face	Purpose
Critical	Information that requires immediate action — high contrast, used scarcely.
Popout	Information that needs attention, attracted by a clearly different hue.
Strong	Structural information such as titles and keywords — the default color with a heavier weight.
Salient	Important information — a different hue with roughly the same intensity as the default face.
Faded	Less important information such as comments — the default hue family at a lower intensity.
Subtle	Physical delimitation of screen areas through barely perceptible backgrounds.

Compared to the Emacs original, the light background is warmer, the dark background omits the blue tint, and the colors are tuned to meet minimum accessibility contrast requirements.

Features

• 15 variants, with the light and dark palettes selected independently.
• Live variant selector built on vim.ui.select, with previews when the selector UI supports them.
• Transparent backgrounds that retain contrast for selections, searches, diagnostics, and diffs, with optional blended float backgrounds.
• Modern treesitter captures (Neovim 0.10+, with the legacy names kept for older versions), LSP semantic tokens, colored diagnostic undercurls, and inlay hints.
• Terminal colors, a lualine theme that follows runtime variant switches, and integrations for bufferline, copilot, dashboard, fzf-lua, hlslens, indent-blankline, mini.nvim, neogit, neo-tree, noice, notify, telescope, tiny-cmdline, and treesitter.
• A dependency-free headless test suite.

Installation

The suggested installation method is using vim.pack.add in Neovim v0.12+:

vim.pack.add({ "ronisbr/nano-theme.nvim" })
vim.o.background = "light" -- or "dark".
vim.cmd.colorscheme("nano-theme")

With MiniDeps:

MiniDeps.add({ source = "ronisbr/nano-theme.nvim" })
vim.o.background = "light" -- or "dark".
vim.cmd.colorscheme("nano-theme")

Configuration

Call setup before activating the colorscheme to change the defaults:

require("nano-theme").setup({
  light_variant      = "default",
  dark_variant       = "default",
  transparent        = false,
  transparent_floats = true,
  float_blend        = 0,
})
vim.cmd.colorscheme("nano-theme")

Option	Default	Description
light_variant	"default"	Variant applied when background is light.
dark_variant	"default"	Variant applied when background is dark.
transparent	false	Clear background-bearing editor and integration surfaces.
transparent_floats	true	When transparency is on, make NormalFloat, FloatBorder, and FloatTitle fully transparent instead of retaining Nano's float background.
float_blend	0	Integer from 0 through 100 applied to Nano float highlight groups when their background is retained. It does not mutate Neovim's winblend option.

setup validates the variant names and the float options. See :h nano-theme for the full documentation.

Variants

Variant	Description
amber	Amber phosphor CRT monitor palette. Dark mode uses a near-black background with warm golden-amber glowing text; light mode uses a warm parchment background with deep amber ink.
blue	Cool, steel-blue tinted palette where backgrounds and accents lean toward blue tones.
default	Warm, slightly tinted palette faithful to the original N Λ N O Emacs theme.
gilded	Ink, paper, and gold palette — a sibling of ink with a softer, warmer character. Dark mode uses a blue-tinted ink background with warm paper text, a gilded gold salient, and a muted teal popout; light mode uses a warm paper background with dark ink text. Choose ink for maximum neutral contrast, gilded for the tinted, paper-like rendition of the same gold/cool-accent scheme.
gray	Fully desaturated, neutral gray palette. Salient and popout faces use achromatic tones for a monochrome feel.
green	Nature-inspired palette with green-tinted backgrounds.
ink	High-contrast variant with near-pure black/white neutral backgrounds and warm amber/blue accent hues. The crisper, fully neutral sibling of gilded.
jinx	Arcane-inspired palette. Both modes share the same role mapping: magenta-pink salient (Jinx's hair), Hextech neon-blue strong, and electric teal-cyan popout. Light mode uses a near-white background with a barely perceptible grey-pink tint; dark mode uses a near-black background with a subtle violet tint.
ocean	Deep marine palette. Light mode is sea glass — a cool aqua-tinted background with deep teal ink and a rust popout; dark mode is deep sea — a blue-green abyss background with a bright cyan-teal salient and a sandy amber popout. Leans teal where blue leans steel.
old_terminal	Retro phosphor monitor palette. Dark mode uses near-black background with bright green text; light mode uses a green-tinted background with dark green text.
orange	Warm, earthy palette with orange-tinted backgrounds and amber accents.
rose	Soft rose-quartz palette. Light mode is dawn — a warm near-white background with a barely perceptible pink tint, a muted raspberry salient, and a sea-glass teal popout; dark mode is dusk — a mauve-tinted near-black background with rosy text and a soft rose salient.
rougier	Palette closest to the original N Λ N O Emacs theme by @rougier, with minimal modifications.
violet	Quiet lavender palette. Light mode uses a lilac-tinted near-white background with a soft violet salient and a warm amber popout; dark mode is aubergine — a violet-tinted near-black background with lavender text. Stays muted where jinx is electric.
wood	Timber-inspired palette. Dark mode is walnut heartwood — a deep espresso background with oak-cream text, a honey salient, and a mahogany popout; light mode is sanded oak — a pale pine background with dark walnut ink, a chestnut salient, and a verdigris popout. Syntax hues are muted toward natural grain and patina tones.

Runtime Controls

Variant Selection

Use :NanoThemeLight or :NanoThemeDark to pick the variant for that background mode. The selector uses Neovim's overrideable vim.ui.select, so it honors any selector UI you configure. When that selector supports and calls preview_item, the highlighted variant is previewed; selecting an item applies it, and cancelling restores the previous colorscheme, background, variants, and transparency settings.

The same selector is available from Lua:

require("nano-theme").select_light_variant()
require("nano-theme").select_dark_variant()

Transparent Backgrounds

Set transparent = true in setup to clear background-bearing surfaces while retaining contrast for selections, searches, diagnostics, and diffs. By default the floats become fully transparent too; for a recommended dark tinted float setup, use:

require("nano-theme").setup({
  transparent = true,
  transparent_floats = false,
  float_blend = 10,
})

Use :NanoThemeTransparent to toggle transparency, or :NanoThemeTransparentEnable and :NanoThemeTransparentDisable to set it explicitly. The equivalent Lua APIs are:

require("nano-theme").toggle_transparent()
require("nano-theme").set_transparent(true)  -- enable
require("nano-theme").set_transparent(false) -- disable

When nano-theme is active, these commands and functions reapply it immediately. Otherwise, they update the state without changing the active colorscheme.

Development

Run the dependency-free headless test suite from the repository root:

make test

The logo and the variants panel are generated from the palette definitions in lua/nano-theme/colors, so they always match the code:

make logo   # screenshots/logo-light.svg and logo-dark.svg
make panel  # screenshots/variants.svg and variants.png (also refreshes the logo)

Rendering the panel PNG requires librsvg (rsvg-convert) or resvg; when pngquant is available, the PNG is also optimized.

License

nano-theme.nvim is licensed under the GNU General Public License v3.0. See LICENSE.txt for details.