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cyan · cool

#237fac

a dark, vivid cyan · cool · closest name: Steel Blue

Token name suggestion: Dusk Teal

RGB
35, 127, 172
HSL
200°, 66%, 41%
CMYK
80, 26, 0, 33
Luminance
0.1851

#237fac is a dark vivid cyan, 200° on the wheel and 96/100 on the cool side. Put black text on it (4.70:1). As text it scores 4.47:1 on white — large text only. Nearest name is Steel Blue, nearest Tailwind family is blue.

hsl(200 66% 41%)rgb(35 127 172)Base step 700AA inkCool

At a glance

Every number on this page in one read: what #237fac is made of, how bright it looks, and which way it leans.

Hex
#237fac
Hue
200°
cyan
Saturation
66%
vivid
Lightness
41%
dark
Brightness
67%
HSV value
Perceived
45%
weighted brightness
Luminance
0.1851
WCAG relative
Temperature
Cool
96/100 cool
Color family
Cyan
Tone
Vivid
Best ink
Black
4.70:1
Closest name
Steel Blue
ΔE2000 5
Chroma
33.0
LCH, 0–130ish
OKLCH L
0.565
perceptual lightness
Tailwind
blue
500 · ΔE 11.8
Web-safe
#336699
nearest of 216
Where it sits
Hue200° of 360°
Saturation66%
Lightness41%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #237fac.

Temperature
Warm ← → Cool96% cool

Reads cool. Warm and cool siblings keep the same lightness, so you can swap one in without redoing your contrast maths.

Luminance by channel
Red2%
Green82%
Blue16%

Green carries most of what the eye calls brightness — that is why WCAG weights it 0.7152.

Every format

HEX#237fac
HEX (8-digit)#237facff
RGBrgb(35, 127, 172)
RGBArgba(35, 127, 172, 1)
HSLhsl(200, 66%, 41%)
HSV / HSBhsv(200, 80%, 67%)
HWBhwb(200 14% 33%)
CMYKcmyk(80%, 26%, 0%, 33%)
LABlab(50.1 -10.5 -31.3)
LCHlch(50.1 33.0 251.5)
OKLCHoklch(0.565 0.108 235.2)
XYZ (D65)xyz(15.73, 18.51, 41.77)
Decimal2326444
Display P3color(display-p3 0.137 0.498 0.675)
Web-safe#336699

Copy-ready code

every platformclick to select
/* CSS */
color: #237fac;
background-color: #237fac;
/* CSS custom property */
--brand: #237fac;
/* Tailwind (arbitrary) */
class="text-[#237fac] bg-[#237fac]"
/* SCSS */
$brand: #237fac;
/* SwiftUI */
Color(red: 0.137, green: 0.498, blue: 0.675)
/* UIKit */
UIColor(red: 0.137, green: 0.498, blue: 0.675, alpha: 1)
/* Android XML */
<color name="brand">#237FAC</color>
/* Android Compose */
Color(0xFF237FAC)
/* Flutter */
Color(0xFF237FAC)
/* Python / OpenCV (BGR) */
(172, 127, 35)
/* Python / PIL (RGB) */
(35, 127, 172)
/* Java AWT */
new Color(35, 127, 172)
/* .NET */
Color.FromArgb(255, 35, 127, 172)
/* OpenGL / Unity (0–1) */
(0.1373f, 0.4980f, 0.6745f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{35,127,172}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #237fac 85%, white);
border-color: color-mix(in oklab, #237fac 40%, transparent);
/* theme-aware in one line */
color: light-dark(#164E6A, #D3E5EE);
/* relative colour syntax */
--hover: hsl(from #237fac h s calc(l - 7));

Design tokens

The same ramp in the four formats a team actually needs. Paste one and the whole palette lands with it.

css custom propertiesclick to select
:root {
  --brand-50: #F3F9FB;
  --brand-100: #E8F2F8;
  --brand-200: #CBE4F1;
  --brand-300: #A2D4EC;
  --brand-400: #73BEE3;
  --brand-500: #45A8D9;
  --brand-600: #2996CB;
  --brand-700: #237fac;
  --brand-800: #1C6488;
  --brand-900: #184A62;
  --brand-950: #0F2E3E;
  --brand: #237fac;
  --brand-ink: #000000;
  --brand-surface: #F4F8FA;
  --brand-border: #C0DEED;
  --brand-hover: #1D698E;
  --brand-pressed: #175371;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #141F24;
    --brand-ink: #D3E5EE;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F3F9FB',
        100: '#E8F2F8',
        200: '#CBE4F1',
        300: '#A2D4EC',
        400: '#73BEE3',
        500: '#45A8D9',
        600: '#2996CB',
        700: '#237fac',
        800: '#1C6488',
        900: '#184A62',
        950: '#0F2E3E',
        DEFAULT: '#237fac',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F3F9FB,
  '100': #E8F2F8,
  '200': #CBE4F1,
  '300': #A2D4EC,
  '400': #73BEE3,
  '500': #45A8D9,
  '600': #2996CB,
  '700': #237fac,
  '800': #1C6488,
  '900': #184A62,
  '950': #0F2E3E,
);
$brand-base: #237fac;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F3F9FB", "$type": "color" },
      "100": { "$value": "#E8F2F8", "$type": "color" },
      "200": { "$value": "#CBE4F1", "$type": "color" },
      "300": { "$value": "#A2D4EC", "$type": "color" },
      "400": { "$value": "#73BEE3", "$type": "color" },
      "500": { "$value": "#45A8D9", "$type": "color" },
      "600": { "$value": "#2996CB", "$type": "color" },
      "700": { "$value": "#237fac", "$type": "color" },
      "800": { "$value": "#1C6488", "$type": "color" },
      "900": { "$value": "#184A62", "$type": "color" },
      "950": { "$value": "#0F2E3E", "$type": "color" }
    },
    "brandInk": { "$value": "#000000", "$type": "color" }
  }
}

Best text color

Only one of black and white can be right. This is the one, with the number that proves it.

Readable at a glance#000000 on #237fac · 4.70:1
Use #000000AA at every size, AAA for large text only.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 4.47:1
AA fail · AA large pass · AAA fail
Aa
Black text · 4.70:1 · recommended
AA pass · AA large pass · AAA fail
Reading the other direction: #237fac as text scores 4.47:1 on white and 4.70:1 on black.
Best tinted ink on it, if plain black or white feels flat: #164E6A at 2.02:1.

Make it accessible

A contrast checker tells you that you failed. This tells you what to ship instead — same hue, same saturation, lightness moved only as far as WCAG demands.

The quick fox
#227CA8 · 4.65:1
AA on white−1% L
#227CA8
The quick fox
#1A5D7D · 7.23:1
AAA on white−11% L
#1A5D7D
The quick fox
#237fac · 4.70:1
AA on blackalready passes
#237fac
The quick fox
#32A0D5 · 7.12:1
AAA on black+11% L
#32A0D5

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #237FAC is enough for headings on white. Non-text elements such as icons, chart strokes and focus rings also sit at 3:1 under WCAG 2.2 (1.4.11).

Accessibility — WCAG contrast

Aa
#237fac on white: 4.47:1
AA ✗ fail · AA-large · AAA
Aa
#237fac on black: 4.70:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #237fac as text on that neutral, and that neutral as text on #237fac.

NeutralRatioBoth directions
White4.47:1AaAa
Slate 504.27:1AaAa
Slate 1004.08:1AaAa
Slate 2003.62:1AaAa
Slate 3003.01:1AaAa
Slate 4001.74:1AaAa
Slate 5001.07:1AaAa
Slate 6001.70:1AaAa
Slate 7002.32:1AaAa
Slate 8003.28:1AaAa
Slate 9004.00:1AaAa
Black4.70:1AaAa
Colour vision deficiency
true color
protanopia · #697EAE
deuteranopia · #5772AB
tritanopia · #008B8E

Roughly one man in twelve has some form of colour vision deficiency. If any of the three panels above is hard to tell apart from a neighbouring colour in your palette, add a shape, an icon or a label so the meaning does not rest on hue alone.

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #237fac is pinned to step 700; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F3F9FB
#E8F2F8
#CBE4F1
#A2D4EC
#73BEE3
#45A8D9
#2996CB
#237fac
#1C6488
#184A62
#0F2E3E
Base = 700Lightest = 50 · #F3F9FBDarkest = 950 · #0F2E3EText step on white = 800
Perceptual ramp — OKLCH

The same eleven steps expressed in OKLCH, where equal lightness numbers actually look equally spaced. HSL ramps go muddy in the yellows and washed out in the blues; this one does not. Modern browsers render it natively — the hex ramp above is the fallback.

50100200300400500600700800900950
oklch tokensclick to select
:root {
  --brand-50: oklch(0.97 0.027 235.2);
  --brand-100: oklch(0.94 0.043 235.2);
  --brand-200: oklch(0.88 0.065 235.2);
  --brand-300: oklch(0.80 0.084 235.2);
  --brand-400: oklch(0.72 0.099 235.2);
  --brand-500: oklch(0.64 0.108 235.2);
  --brand-600: oklch(0.56 0.108 235.2);
  --brand-700: oklch(0.48 0.101 235.2);
  --brand-800: oklch(0.40 0.090 235.2);
  --brand-900: oklch(0.32 0.075 235.2);
  --brand-950: oklch(0.24 0.059 235.2);
}

Colors that work with #237fac

Not a palette — a role sheet. Each swatch answers one question you will hit while building the component.

Text on it#000000
Black wins here
Surface#F4F8FA
Tinted page background
Border#C0DEED
Hairlines and dividers
Muted text#4B819B
Captions on the surface
Accent#B02A1F
Second voice, not a rival
Dark variant#164E6A
Hover, pressed, headers
Light variant#EAF5FB
Selected rows, tints
Dark surface#141F24
Dark-mode background
Hover#1D698E
One step down in lightness
Pressed#175371
Two steps down
Disabled#8BA7B5
Chroma pulled out
Focus ring#1B8FC8
Offset from the fill so it reads
Light mode
Everything in its place

Surface, border, heading and body all derive from this one hue, so the screen stays coherent without a second palette.

Primary actionSecondaryBadge
Dark mode
Same hue, inverted

Lightness flips, hue holds. The accent stays the anchor in both themes.

Primary actionSecondaryAccent

In real components

The same eight roles, wired into the interface patterns you will actually build with them. Every state below is a computed value, not a mock-up.

Buttons and states
Save changesHoverPressedDisabled
OutlineSubtleLinkFocused
Form field
you@company.com

Focus ring uses the light variant so the field still reads as one shape.

Send me product updates
Notice
Your export is ready

The file stays available for seven days. Download it before it expires.

NewBetaDraft
Data
Storage used68%
Acme LtdActive
NorthwindTrial
GlobexActive

How to use #237fac

Derived from its contrast, chroma and lightness — not from taste.

Works well for
  • Headings from 24px up on white
  • Text and icons on dark surfaces
  • Primary buttons and calls to action
  • Focus rings, active and selected states
  • Headers, footers and dark-mode surfaces
  • Brand accents, badges and data highlights
Use with care
  • Small text on white — under 4.5:1
  • Full-page backgrounds — tiring over long sessions
  • Black text placed on it
  • Thin strokes and 1px borders — they disappear on light UI
  • Pairing with a same-lightness hue — edges vibrate
Minimum size as text on white
24px / 18.66px bold
Safe as a fill behind white type
No — use #164E6A
Safe as a 1px border on white
Yes

Meaning and mood

What a colour in this family tends to signal, and how this particular chroma and lightness change the reading.

cleantechnicalfreshclinical

Cyan reads as water, air and infrastructure: cool, hygienic, engineered.

This is a confident chroma: strong enough to lead a brand, restrained enough to live in an interface all day. The low lightness adds weight and formality.

Worth knowing

At high lightness it disappears into white surfaces and thin strokes vanish entirely.

Reads as
  • FormalityHigh
  • EnergyMedium-high
  • Weight59/100
  • TemperatureCool
  • ApproachabilityReserved

Colour associations are cultural and vary by market. Treat these as a starting point for a conversation with your audience, not a finding about them.

Similar colors

One move away from this hex in each direction. Every swatch is its own page.

Color relationships

The wheel positions with their names attached, so you can grab the one you actually need.

Complementary#AC5023
Analogous left#23AC95
Analogous right#233BAC
Split-complement 1#AC233B
Split-complement 2#AC9523
Triadic 1#AC237F
Triadic 2#7FAC23
Tetradic#9523AC
On the wheel
Base+30°−30°+120°+240°+180°200°

#237fac sits at 200°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red13.7%
Green49.8%
Blue67.5%
R · 0–255
35
0x23
G · 0–255
127
0x7f
B · 0–255
172
0xac

CMYK percentages

Cyan79.7%
Magenta26.2%
Yellow0.0%
Key (black)32.5%

Total ink coverage is 138%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#237fac text on a black background

contrast 4.70:1

Card sample

#237fac text on a white background

contrast 4.47:1

Card sample

#237fac on grey

4.08:1

#237fac on its own surface

4.18:1

#237fac on its dark surface

3.76:1

CSS3 live lab

Text font color

The quick brown fox

color: #237fac;
Background color
Panel with #237fac background
background-color: #237fac;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #237fac;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(35, 127, 172, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(35, 127, 172, 0.45);
Border & gradient
Gradient panel
border: 3px solid #237fac;
background: linear-gradient(135deg, #237fac, #2324AC);
Gradient text

Gradient headline

background: linear-gradient(90deg, #237fac, #4523AC);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #237fac;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #237fac;
caret-color: #237fac;
Left rule
Pull quote or callout
border-left: 4px solid #237fac;
Ring + tint
Selected chip
background: #EAF5FB;
box-shadow: inset 0 0 0 2px #237fac;
Conic badge
68%
background: conic-gradient(#237fac 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #237fac over white; the bottom row is the same alpha over a checkerboard, so you can see what survives on a photo or a video.

Bottom row of hexes is the flattened result over white — use those when a design tool refuses transparency, or when you need a solid fallback.

alpha in every syntaxclick to select
rgba(35, 127, 172, 0.5)
rgb(35 127 172 / 50%)
#237fac80
hsl(200 66% 41% / 50%)
color-mix(in srgb, #237fac 50%, transparent)
Alpha8-digit hexFlat on white
10%#237fac1a#E9F2F7
20%#237fac33#D3E5EE
40%#237fac66#A7CCDE
60%#237fac99#7BB2CD
80%#237faccc#4F99BD

Gradients from #237fac

Six recipes, each built from this hex and shown with the exact CSS that produced it.

Elevation
Same hue, three lightnesses — safe anywhere
background: linear-gradient(135deg, #36A2D6, #237fac 45%, #164E6A);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #237fac, #271E93);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #237fac, #AC5023);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #50ADDB 0%, #237fac 45%, #164E6A 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F4F8FA, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #2ED4AA 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #2836C5 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #164E6A 0%, transparent 65%), #237fac;

Monochromatic scale

Palettes built from #237fac

Shades — darker

Tints — lighter

Tones — desaturated

Color harmonies

Nearest named colors

Ranked with CIEDE2000 across all 139 CSS keywords. Under ΔE 2 the eye stops telling them apart; over ΔE 10 they are plainly different colors.

#237fac in the real world

Where a color in this family tends to land, and the interface roles it is usually asked to play.

Industries
TechnologyTravelHealthcareMedia
Common UI roles
ButtonsLinksFocus statesCharts
Print note

Converts to four-color process without much drama. Proof it anyway.

On screens

Holds up across typical panel gamma. Still worth checking on an uncalibrated laptop, where mid-tones shift most.

In dark mode

Usable as-is on a dark surface at 4.70:1.

Explore nearby colors

Small, deliberate steps away from this hex — useful when you are hunting for the version of a colour that finally feels right.

#237fac, answered

What color is #237fac?

#237fac is a dark vivid cyan, closest to Steel Blue (ΔE2000 5). It sits at 200° on the hue wheel with 66% saturation and 41% lightness, which reads as cool.

What is the RGB value of #237fac?

rgb(35, 127, 172) — 35 red, 127 green and 172 blue out of 255, or 13.7% / 49.8% / 67.5% by channel.

What is #237fac in HSL and HSV?

hsl(200, 66%, 41%) and hsv(200, 80%, 67%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #237fac a light or a dark color?

It is a mid-tone. Relative luminance is 0.1851 and perceived brightness is 45%, so black text on it reaches 4.70:1.

Should I use black or white text on #237fac?

Black. It scores 4.70:1 against #237fac, versus 4.47:1 for white — AA at any size.

Is #237fac accessible on a white background?

#237fac on white scores 4.47:1, which only clears AA for large text — 18.66px bold or 24px regular and up. Darken it to #227CA8 to reach 4.5:1, or #1A5D7D for 7:1.

What is the complementary color of #237fac?

#AC5023 sits directly opposite on the wheel. Softer options are the split-complements #AC233B and #AC9523, which give the same contrast with far less vibration.

What colors go well with #237fac?

For interface work: #F4F8FA as the surface, #C0DEED for borders, #4B819B for secondary text, #B02A1F as an accent and #164E6A for hover and pressed states. For a palette, the analogous pair #23AC95 and #233BAC stays calm, while #AC5023 is the loudest partner.

What is #237fac in CMYK for printing?

cmyk(80%, 26%, 0%, 33%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #237fac warm or cool?

Cool — it scores 96 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #23ACA7; nudged cooler, #216FAE.

Which Tailwind color is closest to #237fac?

The blue family — its 500 step is #3b82f6, ΔE2000 11.8 away. That is a visible difference, so define #237fac as a custom token rather than reaching for the built-in.

How do I use #237fac in Tailwind CSS?

Inline it as an arbitrary value with bg-[#237fac] or text-[#237fac], or register the whole ramp under theme.extend.colors.brand so you get bg-brand-500 and friends. The generated 50–950 scale on this page is ready to paste into your config.

What is #237fac with 50% opacity?

rgba(35, 127, 172, 0.5), or #237fac80 in eight-digit hex. Over white that composites to #91BFD6; over black, #124056.

Is #237fac a web-safe color?

No. The nearest web-safe colour is #336699, ΔE2000 10.6 away. The palette only matters for legacy displays and some email clients now.

What does the color #237fac mean?

As a cyan, it reads clean, technical, fresh. Cyan reads as water, air and infrastructure: cool, hygienic, engineered. At this chroma the effect is amplified — it will dominate whatever sits beside it.

What gradient works with #237fac?

The safest is same-hue elevation: linear-gradient(135deg, #36A2D6, #237fac 45%, #164E6A). For more colour, a short hue run to #271E93 keeps it rich without turning muddy.

Work with #237fac in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #237fac at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.