Blue Hour _{Font: Geist Mono. The file is samples/blue-hour.ts, colored by the theme.}

Blue Hour

A minimal dark theme for Cursor and VS Code, modeled on a room at blue hour: a near-black floor, blue accents and warm highlights. Most of the code is gray, with two blues for keywords and calls and a peach and a gold for strings and numbers.

Install

Cursor: Open VSX · VS Code: Marketplace · or grab the .vsix from Releases and use Extensions: Install from VSIX…
Then Cmd+K Cmd+T and pick Blue Hour. You can also try it in the browser on vscode.dev.

How it works

The whole theme is minimal: one background, two color families, and gray for everything else.

One background. The editor, sidebar, tabs, panels and status bar are all the same near-black, with thin lines between them instead of lighter panels. I wanted one calm, cohesive base under everything. The near-black is the floor of the room.
Two color families. Blue hour is blue accents and warm highlights, so there is one cool family and one warm one. Keywords and tags are a soft blue, calls and types a lighter sky. Strings are peach, numbers and constants a lighter gold. I tried six full colors and it read easily but looked like every other theme. I tried making these four stronger and it turned into a blue theme, so they stay soft.
Everything else is gray. This is the minimalism again: with so little color, contrast against the near-black does the rest. Names are the brightest gray in code. Punctuation is darker so the names stand out, comments are darker again, and line numbers are darker still. Calls keep a color because I find my place in a line by color, and an all-gray line gave me nothing to look for.

No italics and no bold in code. In Markdown, headings are bold and your own emphasis renders as written. Red only shows up for errors, invalid code, deletions and merge conflicts, and green only for additions and new files.

The ladder

The ladder is the table below: every color sits on a lightness step, from the background up to the brightest text. The blue and the peach come from photos of the room, the sofa and the lamp. Colors sampled straight from the photos looked washed out on a screen, so I kept the hues and set each value by hand in OKLCH. Each one is checked against the background with tools/colortool.py for WCAG ratio and APCA contrast (the Lc column). Names are Lc 80 and frame text is 70. Punctuation (43), comments (34) and line numbers (21) are lower on purpose, so you read them after the names.

key	used for	hex	OKLCH L	chroma	hue	APCA Lc
`ground`	editor, sidebar, tabs, panels, status bar, terminal; text on badges and buttons; ANSI black	`#141414`	0.19	0	—	—
`raised`	line highlight, inputs, hover, inactive list selection	`#1D1D1D`	0.23	0	—	—
`hairline`	borders, guides, whitespace, secondary buttons	`#2B2B2B`	0.29	0	—	—
`muted`	line numbers, inactive frame text, placeholders, hints, scrollbars, the active tab's line; ANSI bright black	`#636363`	0.50	0	—	21
`comment`	comments, docstrings, block quotes	`#808080`	0.60	0	—	34
`subtle`	punctuation, operators, the active line number, inactive tabs, breadcrumbs, icons, bracket pairs 1 and 4	`#929292`	0.66	0	—	43
`frame`	frame text you read: explorer, status bar, headers, the active tab's label; default editor and terminal text; ANSI white	`#C4C4C4`	0.82	0	—	70
`text`	names: variables, properties, parameters	`#D4D4D4`	0.87	0	—	80
`bright`	carets, Markdown headings; ANSI bright white	`#E8E8E8`	0.93	0	—	92
`blue`	keywords, tags, focus, badges, links, primary buttons, info, the gutter's modified bar, bracket pairs 2 and 5; ANSI blue	`#8EA7C4`	0.72	0.051	252	53
`sky`	calls, types, decorators, link hover; ANSI cyan	`#A9D1EA`	0.84	0.055	236	75
`peach`	strings, matched text in lists, progress bar	`#E6A68A`	0.78	0.085	45	61
`gold`	numbers, constants, escapes, warnings, git modified, bracket pairs 3 and 6; ANSI yellow	`#ECCAAD`	0.86	0.055	62	77
`red`	errors, deletions, conflicts, invalid; ANSI red	`#DA827B`	0.70	0.110	25	47
`green`	additions, untracked, diff inserted; ANSI green	`#92BE9A`	0.76	0.069	150	61
`magenta`	ANSI magenta only	`#BAA8D0`	0.76	0.060	305	58
`highlight_low`	inactive selection, the explorer's open file, word and bracket match, other find matches, list and menu focus, the status bar while debugging	`#1E2A37`	0.28	0.029	251	—
`highlight_mid`	selection, strong word match, terminal selection	`#26394F`	0.34	0.046	253	—
`highlight_high`	the current find match	`#344F6D`	0.42	0.060	252	—
`red_bright`	ANSI bright red (the Claude Code spark)	`#F19E97`	0.78	0.100	25	61
`green_bright`	ANSI bright green	`#ABD8B3`	0.84	0.070	150	76
`gold_bright`	ANSI bright yellow	`#FFDEC1`	0.92	0.053	63	90
`blue_bright`	ANSI bright blue	`#ADC7E4`	0.82	0.050	251	70
`magenta_bright`	ANSI bright magenta	`#D2C3E5`	0.84	0.049	305	73
`sky_bright`	ANSI bright cyan	`#BFE4FB`	0.90	0.050	235	86

Frame text you actually read (explorer, status bar, headers) is one step below the code. Inactive tabs and breadcrumbs are one step below that, and line numbers and placeholders are lower still. The terminal has more colors than the editor because ANSI needs eight: magenta exists only for it, and each colored bright is its base one step up. palette.json holds these values under these names, the theme's token rules use the same names, and python3 tools/check.py fails if any of the three drift.

Working on it

See it: open this folder in Cursor and press F5, or run cursor --extensionDevelopmentPath="$PWD" "$PWD/samples". The samples/ folder pins the theme to that window only. Its files cover TypeScript, TSX, Python, YAML, Markdown, JSON, shell, CSS, Prisma and SQL.
Check a color: python3 tools/colortool.py '#141414' '#E6A68A' prints OKLCH, WCAG and APCA against the background. Check the names: python3 tools/check.py.
Build: npx @vscode/vsce package, then cursor --install-extension bluehour-<version>.vsix.
Rules, commands and how the hero is made: AGENTS.md.

Design notes

How it got here, what I tried and threw away, and the sources: design-notes.md. What shipped when: CHANGELOG.md.

Blue Hour

Luca Caputo

Blue Hour

Install

How it works

The ladder

Working on it

Design notes

License