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#81b3df

a light, vivid blue · cool · closest name: Light Sky Blue

RGB
129, 179, 223
HSL
208°, 60%, 69%
CMYK
42, 20, 0, 13
Luminance
0.4224

At a glance

Every number on this page in one read: what #81b3df is made of, how bright it looks, and which way it leans.

Hex
#81b3df
Hue
208°
blue
Saturation
60%
vivid
Lightness
69%
light
Brightness
87%
HSV value
Perceived
67%
weighted brightness
Luminance
0.4224
WCAG relative
Temperature
Cool
99/100 cool
Color family
Blue
Tone
Vivid
Best ink
Black
9.45:1
Closest name
Light Sky Blue
ΔE2000 7.5
Where it sits
Hue208° of 360°
Saturation60%
Lightness69%
Temperature
Warm ← → Cool99% cool

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

Every format

HEX#81b3df
RGBrgb(129, 179, 223)
HSLhsl(208, 60%, 69%)
CMYKcmyk(42%, 20%, 0%, 13%)
LABlab(71.0 -5.2 -27.3)
LCHlch(71.0 27.8 259.2)
OKLCHoklch(0.748 0.083 245.8)
Decimal8500191
Display P3color(display-p3 0.506 0.702 0.875)

Copy-ready code

/* CSS */
color: #81b3df;
background-color: #81b3df;
/* Tailwind (arbitrary) */
class="text-[#81b3df] bg-[#81b3df]"
/* SCSS */
$brand: #81b3df;
/* SwiftUI */
Color(red: 0.506, green: 0.702, blue: 0.875)
/* Android */
Color.parseColor("#81b3df")
/* Flutter */
Color(0xFF81B3DF)
/* Python / OpenCV (BGR) */
(223, 179, 129)

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 #81b3df · 9.45:1
Use #000000AAA at every size.
Aa
White text · 2.22:1
AA fail · AA large fail · AAA fail
Aa
Black text · 9.45:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #81b3df as text scores 2.22:1 on white and 9.45:1 on black.

Accessibility — WCAG contrast

Aa
#81b3df on white: 2.22:1
AA ✗ fail · AA-large · AAA
Aa
#81b3df on black: 9.45:1
AA ✓ pass · AA-large · AAA
true color
protanopia · #A1B3E1
deuteranopia · #95AADE
tritanopia · #5DBDC2

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #81b3df is pinned to step 400; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F4F8FB
#E9F0F7
#CCDFEF
#A6C9E8
#81b3df
#4C93D2
#327FC3
#296AA3
#215582
#1C3F5F
#11283B
Base = 400Lightest = 50 · #F4F8FBDarkest = 950 · #11283B
:root {
  --brand-50: #F4F8FB;
  --brand-100: #E9F0F7;
  --brand-200: #CCDFEF;
  --brand-300: #A6C9E8;
  --brand-400: #81b3df;
  --brand-500: #4C93D2;
  --brand-600: #327FC3;
  --brand-700: #296AA3;
  --brand-800: #215582;
  --brand-900: #1C3F5F;
  --brand-950: #11283B;
  --brand: #81b3df;
  --brand-ink: #000000;
}

Colors that work with #81b3df

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#C0D8ED
Hairlines and dividers
Muted text#4B759B
Captions on the surface
Accent#A74225
Second voice, not a rival
Dark variant#1A4266
Hover, pressed, headers
Light variant#EBF3FA
Selected rows, tints
Dark surface#141D24
Dark-mode background
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

How to use #81b3df

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

Works well for
  • Text and icons on dark surfaces
  • Primary buttons and calls to action
  • Focus rings, active and selected states
  • Card and section backgrounds
  • Brand accents, badges and data highlights
Use with care
  • Text of any size on white — fails WCAG AA
  • Full-page backgrounds — tiring over long sessions
  • White text placed on it
  • Pairing with a same-lightness hue — edges vibrate

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#DFAD81
Analogous left#81DFDC
Analogous right#8184DF
Split-complement 1#DF8184
Split-complement 2#DFDC81
Triadic 1#DF81B3
Triadic 2#B3DF81
Tetradic#DC81DF

RGB percentages

Red50.6%
Green70.2%
Blue87.5%

CMYK percentages

Cyan42.2%
Magenta19.7%
Yellow0.0%
Key (black)12.5%

Color previews

#81b3df text on a black background

contrast 9.45:1

Card sample

#81b3df text on a white background

contrast 2.22:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #81b3df;
Background color
Panel with #81b3df background
background-color: #81b3df;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #81b3df;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(129, 179, 223, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(129, 179, 223, 0.45);
Border & gradient
Gradient panel
border: 3px solid #81b3df;
background: linear-gradient(135deg, #81b3df, #8E81DF);

Monochromatic scale

Palettes built from #81b3df

Shades — darker

Tints — lighter

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.

#81b3df in the real world

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

Industries
TechnologyFinanceHealthcareEnterprise SaaS
Common UI roles
SurfacesBadgesHighlightsEmpty states
Print note

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

#81b3df, answered

What color is #81b3df?

#81b3df is a light vivid blue, closest to Light Sky Blue (ΔE2000 7.5). It sits at 208° on the hue wheel with 60% saturation and 69% lightness, which reads as cool.

What is the RGB value of #81b3df?

rgb(129, 179, 223) — 129 red, 179 green and 223 blue out of 255, or 50.6% / 70.2% / 87.5% by channel.

Is #81b3df a light or a dark color?

It is a mid-tone. Relative luminance is 0.4224 and perceived brightness is 67%, so black text on it reaches 9.45:1.

Should I use black or white text on #81b3df?

Black. It scores 9.45:1 against #81b3df, versus 2.22:1 for white — AAA at any size.

What is the complementary color of #81b3df?

#DFAD81 sits directly opposite on the wheel. Softer options are the split-complements #DF8184 and #DFDC81, which give the same contrast with far less vibration.

What colors go well with #81b3df?

For interface work: #F4F8FA as the surface, #C0D8ED for borders, #4B759B for secondary text, #A74225 as an accent and #1A4266 for hover and pressed states. For a palette, the analogous pair #81DFDC and #8184DF stays calm, while #DFAD81 is the loudest partner.

What is #81b3df in CMYK for printing?

cmyk(42%, 20%, 0%, 13%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #81b3df warm or cool?

Cool — it scores 99 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #8190DF; nudged cooler, #6BA2DC.

Work with #81b3df in the Color Lab