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cyan · cool

#28433f

a deep, soft cyan · cool · closest name: Dark Slate Gray

Token name suggestion: Ink Teal

RGB
40, 67, 63
HSL
171°, 25%, 21%
CMYK
40, 0, 6, 74
Luminance
0.0482

#28433f is a deep soft cyan, 171° on the wheel and 74/100 on the cool side. Put white text on it (10.69:1). As text it scores 10.69:1 on white — safe at any size. Nearest name is Dark Slate Gray, nearest Tailwind family is neutral.

hsl(171 25% 21%)rgb(40 67 63)Base step 900AAA inkCool

At a glance

Every number on this page in one read: what #28433f is made of, how bright it looks, and which way it leans.

Hex
#28433f
Hue
171°
cyan
Saturation
25%
soft
Lightness
21%
deep
Brightness
26%
HSV value
Perceived
23%
weighted brightness
Luminance
0.0482
WCAG relative
Temperature
Cool
74/100 cool
Color family
Cyan
Tone
Soft
Best ink
White
10.69:1
Closest name
Dark Slate Gray
ΔE2000 4.5
Chroma
11.4
LCH, 0–130ish
OKLCH L
0.360
perceptual lightness
Tailwind
neutral
500 · ΔE 22.5
Web-safe
#333333
nearest of 216
Where it sits
Hue171° of 360°
Saturation25%
Lightness21%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #28433f.

Temperature
Warm ← → Cool74% 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
Red9%
Green83%
Blue7%

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

Every format

HEX#28433f
HEX (8-digit)#28433fff
RGBrgb(40, 67, 63)
RGBArgba(40, 67, 63, 1)
HSLhsl(171, 25%, 21%)
HSV / HSBhsv(171, 40%, 26%)
HWBhwb(171 16% 74%)
CMYKcmyk(40%, 0%, 6%, 74%)
LABlab(26.2 -11.4 -0.8)
LCHlch(26.2 11.4 184.2)
OKLCHoklch(0.360 0.034 184.1)
XYZ (D65)xyz(3.78, 4.82, 5.43)
Decimal2638655
Display P3color(display-p3 0.157 0.263 0.247)
Web-safe#333333

Copy-ready code

every platformclick to select
/* CSS */
color: #28433f;
background-color: #28433f;
/* CSS custom property */
--brand: #28433f;
/* Tailwind (arbitrary) */
class="text-[#28433f] bg-[#28433f]"
/* SCSS */
$brand: #28433f;
/* SwiftUI */
Color(red: 0.157, green: 0.263, blue: 0.247)
/* UIKit */
UIColor(red: 0.157, green: 0.263, blue: 0.247, alpha: 1)
/* Android XML */
<color name="brand">#28433F</color>
/* Android Compose */
Color(0xFF28433F)
/* Flutter */
Color(0xFF28433F)
/* Python / OpenCV (BGR) */
(63, 67, 40)
/* Python / PIL (RGB) */
(40, 67, 63)
/* Java AWT */
new Color(40, 67, 63)
/* .NET */
Color.FromArgb(255, 40, 67, 63)
/* OpenGL / Unity (0–1) */
(0.1569f, 0.2627f, 0.2471f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{40,67,63}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #28433f 85%, white);
border-color: color-mix(in oklab, #28433f 40%, transparent);
/* theme-aware in one line */
color: light-dark(#30504B, #D9E8E6);
/* relative colour syntax */
--hover: hsl(from #28433f 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: #F6F9F8;
  --brand-100: #EDF3F2;
  --brand-200: #D6E5E3;
  --brand-300: #B9D5D1;
  --brand-400: #96C0BA;
  --brand-500: #73ABA3;
  --brand-600: #5C9990;
  --brand-700: #4C8078;
  --brand-800: #3D6660;
  --brand-900: #28433f;
  --brand-950: #1D2F2C;
  --brand: #28433f;
  --brand-ink: #ffffff;
  --brand-surface: #F5F9F9;
  --brand-border: #CCE0DD;
  --brand-hover: #1B2D2A;
  --brand-pressed: #0D1615;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #152321;
    --brand-ink: #D9E8E6;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F6F9F8',
        100: '#EDF3F2',
        200: '#D6E5E3',
        300: '#B9D5D1',
        400: '#96C0BA',
        500: '#73ABA3',
        600: '#5C9990',
        700: '#4C8078',
        800: '#3D6660',
        900: '#28433f',
        950: '#1D2F2C',
        DEFAULT: '#28433f',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F6F9F8,
  '100': #EDF3F2,
  '200': #D6E5E3,
  '300': #B9D5D1,
  '400': #96C0BA,
  '500': #73ABA3,
  '600': #5C9990,
  '700': #4C8078,
  '800': #3D6660,
  '900': #28433f,
  '950': #1D2F2C,
);
$brand-base: #28433f;
$brand-ink: #ffffff;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F6F9F8", "$type": "color" },
      "100": { "$value": "#EDF3F2", "$type": "color" },
      "200": { "$value": "#D6E5E3", "$type": "color" },
      "300": { "$value": "#B9D5D1", "$type": "color" },
      "400": { "$value": "#96C0BA", "$type": "color" },
      "500": { "$value": "#73ABA3", "$type": "color" },
      "600": { "$value": "#5C9990", "$type": "color" },
      "700": { "$value": "#4C8078", "$type": "color" },
      "800": { "$value": "#3D6660", "$type": "color" },
      "900": { "$value": "#28433f", "$type": "color" },
      "950": { "$value": "#1D2F2C", "$type": "color" }
    },
    "brandInk": { "$value": "#ffffff", "$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#ffffff on #28433f · 10.69:1
Use #ffffffAAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 10.69:1 · recommended
AA pass · AA large pass · AAA pass
Aa
Black text · 1.96:1
AA fail · AA large fail · AAA fail
Reading the other direction: #28433f as text scores 10.69:1 on white and 1.96:1 on black.
Best tinted ink on it, if plain black or white feels flat: #EFF5F5 at 9.70:1.

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
#28433f · 10.69:1
AA on whitealready passes
#28433f
The quick fox
#28433f · 10.69:1
AAA on whitealready passes
#28433f
The quick fox
#4C8078 · 4.67:1
AA on black+19% L
#4C8078
The quick fox
#63A298 · 7.15:1
AAA on black+30% L
#63A298

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #28433F 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
#28433f on white: 10.69:1
AA ✓ pass · AA-large · AAA
Aa
#28433f on black: 1.96:1
AA ✗ fail · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #28433f as text on that neutral, and that neutral as text on #28433f.

NeutralRatioBoth directions
White10.69:1AaAa
Slate 5010.22:1AaAa
Slate 1009.76:1AaAa
Slate 2008.67:1AaAa
Slate 3007.20:1AaAa
Slate 4004.17:1AaAa
Slate 5002.25:1AaAa
Slate 6001.41:1AaAa
Slate 7001.03:1AaAa
Slate 8001.37:1AaAa
Slate 9001.67:1AaAa
Black1.96:1AaAa
Colour vision deficiency
true color
protanopia · #41403F
deuteranopia · #3C3D3F
tritanopia · #1F4442

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. #28433f is pinned to step 900; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F6F9F8
#EDF3F2
#D6E5E3
#B9D5D1
#96C0BA
#73ABA3
#5C9990
#4C8078
#3D6660
#28433f
#1D2F2C
Base = 900Lightest = 50 · #F6F9F8Darkest = 950 · #1D2F2CText step on white = 700
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 0.008 184.1);
  --brand-100: oklch(0.94 0.014 184.1);
  --brand-200: oklch(0.88 0.020 184.1);
  --brand-300: oklch(0.80 0.026 184.1);
  --brand-400: oklch(0.72 0.031 184.1);
  --brand-500: oklch(0.64 0.034 184.1);
  --brand-600: oklch(0.56 0.034 184.1);
  --brand-700: oklch(0.48 0.032 184.1);
  --brand-800: oklch(0.40 0.028 184.1);
  --brand-900: oklch(0.32 0.024 184.1);
  --brand-950: oklch(0.24 0.019 184.1);
}

Colors that work with #28433f

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

Text on it#ffffff
White wins here
Surface#F5F9F9
Tinted page background
Border#CCE0DD
Hairlines and dividers
Muted text#569087
Captions on the surface
Accent#452632
Second voice, not a rival
Dark variant#30504B
Hover, pressed, headers
Light variant#EFF5F5
Selected rows, tints
Dark surface#152321
Dark-mode background
Hover#1B2D2A
One step down in lightness
Pressed#0D1615
Two steps down
Disabled#56867F
Chroma pulled out
Focus ring#295650
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 #28433f

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

Works well for
  • Body text and links on white
  • Charts, tags and secondary surfaces
  • Headers, footers and dark-mode surfaces
  • Brand accents, badges and data highlights
Use with care
  • Text on black or near-black surfaces
  • 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
Any size
Safe as a fill behind white type
Yes
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.

The muted chroma softens the association — it reads considered rather than loud, which suits long-form and data-heavy screens. 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
  • Weight79/100
  • 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#43282C
Analogous left#284332
Analogous right#283A43
Split-complement 1#43283A
Split-complement 2#433228
Triadic 1#3F2843
Triadic 2#433F28
Tetradic#322843
On the wheel
Base+30°−30°+120°+240°+180°171°

#28433f sits at 171°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red15.7%
Green26.3%
Blue24.7%
R · 0–255
40
0x28
G · 0–255
67
0x43
B · 0–255
63
0x3f

CMYK percentages

Cyan40.3%
Magenta0.0%
Yellow6.0%
Key (black)73.7%

Total ink coverage is 120%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#28433f text on a black background

contrast 1.96:1

Card sample

#28433f text on a white background

contrast 10.69:1

Card sample

#28433f on grey

9.76:1

#28433f on its own surface

10.08:1

#28433f on its dark surface

1.52:1

CSS3 live lab

Text font color

The quick brown fox

color: #28433f;
Background color
Panel with #28433f background
background-color: #28433f;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #28433f;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(40, 67, 63, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(40, 67, 63, 0.45);
Border & gradient
Gradient panel
border: 3px solid #28433f;
background: linear-gradient(135deg, #28433f, #283543);
Gradient text

Gradient headline

background: linear-gradient(90deg, #28433f, #282E43);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #28433f;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #28433f;
caret-color: #28433f;
Left rule
Pull quote or callout
border-left: 4px solid #28433f;
Ring + tint
Selected chip
background: #EFF5F5;
box-shadow: inset 0 0 0 2px #28433f;
Conic badge
68%
background: conic-gradient(#28433f 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #28433f 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(40, 67, 63, 0.5)
rgb(40 67 63 / 50%)
#28433f80
hsl(171 25% 21% / 50%)
color-mix(in srgb, #28433f 50%, transparent)
Alpha8-digit hexFlat on white
10%#28433f1a#EAECEC
20%#28433f33#D4D9D9
40%#28433f66#A9B4B2
60%#28433f99#7E8E8C
80%#28433fcc#536965

Gradients from #28433f

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, #3F6963, #28433f 45%, #30504B);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #28433f, #1D2430);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #28433f, #43282C);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #4A7D75 0%, #28433f 45%, #30504B 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F5F9F9, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #3B6346 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #334756 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #30504B 0%, transparent 65%), #28433f;

Monochromatic scale

Palettes built from #28433f

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.

#28433f 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

Very dark values collapse into each other on cheap panels — leave more lightness between your darkest steps than the numbers suggest.

In dark mode

Too dim on dark surfaces at 1.96:1 — lift it to #4C8078 for body text, or reserve it for fills.

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.

#28433f, answered

What color is #28433f?

#28433f is a deep soft cyan, closest to Dark Slate Gray (ΔE2000 4.5). It sits at 171° on the hue wheel with 25% saturation and 21% lightness, which reads as cool.

What is the RGB value of #28433f?

rgb(40, 67, 63) — 40 red, 67 green and 63 blue out of 255, or 15.7% / 26.3% / 24.7% by channel.

What is #28433f in HSL and HSV?

hsl(171, 25%, 21%) and hsv(171, 40%, 26%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #28433f a light or a dark color?

It is a dark color. Relative luminance is 0.0482 and perceived brightness is 23%, so white text on it reaches 10.69:1.

Should I use black or white text on #28433f?

White. It scores 10.69:1 against #28433f, versus 1.96:1 for black — AAA at any size.

Is #28433f accessible on a white background?

#28433f on white scores 10.69:1, which clears AAA at every size.

What is the complementary color of #28433f?

#43282C sits directly opposite on the wheel. Softer options are the split-complements #43283A and #433228, which give the same contrast with far less vibration.

What colors go well with #28433f?

For interface work: #F5F9F9 as the surface, #CCE0DD for borders, #569087 for secondary text, #452632 as an accent and #30504B for hover and pressed states. For a palette, the analogous pair #284332 and #283A43 stays calm, while #43282C is the loudest partner.

What is #28433f in CMYK for printing?

cmyk(40%, 0%, 6%, 74%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #28433f warm or cool?

Cool — it scores 74 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #284335; nudged cooler, #273E44.

Which Tailwind color is closest to #28433f?

The neutral family — its 500 step is #737373, ΔE2000 22.5 away. That is a visible difference, so define #28433f as a custom token rather than reaching for the built-in.

How do I use #28433f in Tailwind CSS?

Inline it as an arbitrary value with bg-[#28433f] or text-[#28433f], 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 #28433f with 50% opacity?

rgba(40, 67, 63, 0.5), or #28433f80 in eight-digit hex. Over white that composites to #94A19F; over black, #142220.

Is #28433f a web-safe color?

No. The nearest web-safe colour is #333333, ΔE2000 12.8 away. The palette only matters for legacy displays and some email clients now.

What does the color #28433f mean?

As a cyan, it reads clean, technical, fresh. Cyan reads as water, air and infrastructure: cool, hygienic, engineered. At this moderate chroma the association is present but not shouted.

What gradient works with #28433f?

The safest is same-hue elevation: linear-gradient(135deg, #3F6963, #28433f 45%, #30504B). For more colour, a short hue run to #1D2430 keeps it rich without turning muddy.

Work with #28433f in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #28433f at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.