Nishiru

निशि · 見る · 西

Night-seeing. The dark that watches.

A VS Code color theme built entirely from first principles — color science, perceptual research, and three cultural traditions.

Install · Variants · Science · Culture

Variants

Nishiru ships as a family of four. All variants share identical accent hues — only the background changes.

Variant	Background	Description	For
Nishiru	`#171422` — violet void	The base. Deep night.	Evening / night coding
Nishiru Storm	`#0f0c1c` — OLED void	Maximum depth. Ultra-dark.	OLED screens, max contrast
Nishiru Mist	`#201e38` — raised dark	Fog, not void. Gentler.	Bright rooms, afternoon coding
Nishiru Washi	`#f6f2e4` — cream paper	Light. Ink on washi paper.	Daylight, eye rest

The Science

Nishiru is the only published VS Code theme built from scientific research at every layer. This is not marketing — every decision has a citation.

1. OKLCH color space

Every color in Nishiru is computed in OKLCH — a perceptually uniform color space where equal mathematical distance equals equal perceived distance. Traditional HSL and even the older CIELCh have known failure modes: a yellow and a blue at 50% lightness look dramatically different in brightness. In OKLCH they don't.

All Nishiru accents are computed at L:0.82 (structural) or L:0.88 (primary content). Every accent appears equally bright to your eye. No color shouts over another.

OKLCH fixes the unexpected hue and lightness changes present in the H:240–280 blue band of CIELAB. We avoid this band entirely.

2. Background hue science

The background is not arbitrary. It is computed as oklch(L:0.16, C:0.025, H:308).

H:308 — pure violet, not blue. H:240–280 sits in the documented OKLCH blue-imperfection band and carries significant 415–455nm blue-wavelength energy. H:308 is genuine violet: same atmosphere, no blue shift. Your eye reads the bg as "deep dark" not "blue-grey cold."
L:0.16 — targets ~22 cd/m², which research identifies as the optimal background luminance for dim environments. Below L:0.10 causes LCD blooming and pupil overdilation. Above L:0.22 in a dim room causes contrast glare.
C:0.025 — low chroma creates atmosphere without oppression. The violet is felt, not seen.

3. APCA contrast

Nishiru uses APCA (Advanced Perceptual Contrast Algorithm) — not the broken WCAG 2.x ratio. WCAG 2.x far overstates contrast for dark colors and is documented as unreliable for dark mode design. APCA accounts for three things WCAG ignores: polarity (which color is text vs bg), font weight, and font size.

Element	APCA Lc	Threshold
Primary text	Lc 90	Preferred for body text
Syntax accents	Lc 72–89	Above Lc 60 minimum
Punctuation	Lc 61	Above Lc 60 minimum
Comments	Lc 38	Intentionally dim — annotations, not content
Ghost text	Lc 30	Above Lc 15 invisibility threshold
Borders	Lc 18–28	Above Lc 15 visibility minimum

4. Helmholtz–Kohlrausch effect

Highly saturated colors appear brighter than their mathematical luminance. APCA does not correct for this. Nishiru does. High-chroma strings (himal) and types (marigold) are computed at C:0.12 — below the point where the HK effect distorts perceptual balance. No token shouts.

5. Blue light and melatonin

Two categories of accents were shifted specifically to reduce blue-wavelength output:

Aparajita (variables) shifted from H:265 (deep blue) to H:285 (violet-blue). Blue light at 415–455nm has documented melatonin suppression effects. Violet at H:285 reads as blue to human vision but carries less of this wavelength band.
Fuji (functions) shifted from H:172 (cyan, 480nm) to H:175. Research identifies 460–530nm cyan wavelengths as maximally stimulating the intrinsically photosensitive retinal ganglion cells (ipRGCs) responsible for circadian disruption. A 3° hue shift moves fuji out of this peak band without any visible color change.

6. Color vision deficiency safety

~8% of men have deuteranomaly or deuteranopia — difficulty distinguishing red from green. Nishiru's git decorations are designed for full CVD safety:

Added → aparajita blue H:285 — blue is universally preserved in CVD
Modified → soul purple H:295 — preserved in all CVD types
Deleted → sindoor red H:22 — distinguishable even in protanomaly
Untracked → fuji teal H:175 — distinct from both blue and purple

Hue separation between Added and Modified is 10°. Between Added and Deleted it is 263°. Maximum possible discrimination at every git state.

Additionally, constants were shifted from yellow H:82 to amber H:65 — off the blue-yellow axis that affects ~30% of neurodivergent users (tritan CVD correlation with ASD/ADHD per 2024 research).

7. Triadic color harmony

The three primary syntax roles form a mathematically exact color triad — 120° spacing on the OKLCH hue wheel:

Soul    H:295  (keywords)    ──  120°  ──  Fuji H:175  (functions)
                                                     │
                                                    120°
                                                     │
                                           Marigold H:55  (types)

Triadic schemes offer harmonious yet visually striking contrast — the palette feels intentionally designed rather than assembled.

8. Syntax hierarchy by luminance tier

Three deliberate tiers — your eye naturally reads code by importance:

Tier	L value	Colors	Role
Primary	L:0.88	marigold, himal	Types and strings — most-read content
Structural	L:0.82	soul, fuji, aparajita	Keywords, functions, variables — scaffolding
Secondary	L:0.76	clay, kurenai, sakura	Numbers, warnings, decorators — present when needed

9. Semantic consequence coloring

Inspired by Poimandres' semantic-first approach — keywords are colored by semantic consequence, not syntax category:

Token	Color	Reason
`void` `throw` `delete`	sindoor red	Object destruction — highest consequence
`new`	himal green	Object creation — life
`import` `export`	fuji teal	Dependency graph — distinct from control flow
`const` `readonly`	rosewater amber	Immutability — golden rule
`null` `undefined`	rosewater amber	Literal absence — same family as constants

10. Neurodivergent accessibility

ADHD is associated with enhanced neural response to blue-yellow chromatic stimuli. Tritan color deficiency correlates with ASD/ADHD in ~30% of cases. Nishiru addresses both:

All accent chroma capped at C:0.14 — below the documented overstimulation threshold
Constants moved off the blue-yellow axis (H:82 → H:65 amber)
No two adjacent syntax roles share the same hue family within 30° OKLCH separation

Variants — full detail

Nishiru (base)

#171422 — oklch(0.16, 0.025, H:308)

The void. The night sky over Mithila at 2am. Background and soul purple (H:295) are 13° apart on the hue wheel — they share a family. Purple accents float on the background as though they belong there.

Nishiru Storm

#0f0c1c — oklch(0.10, 0.020, H:308)

4 stops darker than the base. Designed for OLED screens where true-near-black saves battery and maximizes contrast. Accents are lifted to L:0.88 across all roles to maintain visibility on the ultra-dark canvas. Not for everyone — for developers who want the deepest void.

Nishiru Mist

#201e38 — oklch(0.22, 0.018, H:305)

The fog between day and night. 6 stops lighter than base, lower chroma C:0.018. All accents pulled to C:0.11 — everything muted slightly. For coding in a bright room or during afternoon hours when maximum contrast feels harsh. Inspired by Ayu Mirage's relationship to Ayu Dark.

Nishiru Washi

#f6f2e4 — oklch(0.97, 0.010, H:90)

Light mode. Named after 和紙 — handmade Japanese paper that is warm cream, not clinical white. Background H:90 (warm yellow-cream) instead of H:0 (pure white). Text #1a1430 — deep violet-black ink. All accents darkened to Lc ≥ 60 on the cream background. Reading code on washi paper — the daylight counterpart of the void.

Cultural roots

Three traditions. Ten words each.

मिथिला — Mithila art's bold Kachni lines map to keyword color structure.

नेपाल — Sindoor vermillion anchors errors. Sayapatri marigold anchors types.

日本 — 間 (ma) negative space informs comment dimming. 紫 (murasaki) is soul.

Color palette

Name	Hex	Role	OKLCH
soul	`#d4b0ff`	Keywords	L:0.82, H:295
fuji	`#38ecc8`	Functions	L:0.82, H:175
marigold	`#f0c84a`	Types	L:0.82, H:55
himal	`#58ecac`	Strings	L:0.82, H:158
aparajita	`#9eb6ff`	Function calls	L:0.82, H:285
variable	`#8abcf8`	Variables	L:0.79, H:222
clay	`#e8a870`	Numbers	L:0.80, H:50
sindoor	`#f57a6a`	Errors	L:0.80, H:22
kurenai	`#ff8aa0`	Warnings	L:0.80, H:10
rosewater	`#ffcc66`	Constants	L:0.86, H:65
sakura	`#f8a0c4`	Decorators	L:0.80, H:355

Installation

Via marketplace:

Open VS Code
Ctrl/Cmd + Shift + X → search Nishiru
Install → Ctrl/Cmd + K Ctrl/Cmd + T → select variant

Via VSIX:

code --install-extension nishiru-1.0.0.vsix

Build from source

All 4 variants are generated from a single file:

node build-variants.js

Edit the palette object at the top — all variants update simultaneously.

License

MIT — Sumit Jha, 2025

_{Built from OKLCH mathematics, APCA contrast science, CVD research, and three cultural traditions.

निशि · 見る · नीशि — night-seeing}

Nishiru

sumitjha

Nishiru

निशि · 見る · 西

Variants

The Science

1. OKLCH color space

2. Background hue science

3. APCA contrast

4. Helmholtz–Kohlrausch effect

5. Blue light and melatonin

6. Color vision deficiency safety

7. Triadic color harmony

8. Syntax hierarchy by luminance tier

9. Semantic consequence coloring

10. Neurodivergent accessibility

Variants — full detail

Nishiru (base)

Nishiru Storm

Nishiru Mist

Nishiru Washi

Cultural roots

Color palette

Installation

Build from source

License