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#1817af

a dark, electric blue · cool · closest name: Medium Blue

RGB
24, 23, 175
HSL
240°, 77%, 39%
CMYK
86, 87, 0, 31
Luminance
0.0390

At a glance

Every number on this page in one read: what #1817af is made of, how bright it looks, and which way it leans.

Hex
#1817af
Hue
240°
blue
Saturation
77%
electric
Lightness
39%
dark
Brightness
69%
HSV value
Perceived
25%
weighted brightness
Luminance
0.0390
WCAG relative
Temperature
Cool
83/100 cool
Color family
Blue
Tone
Electric
Best ink
White
11.79:1
Closest name
Medium Blue
ΔE2000 3.7
Where it sits
Hue240° of 360°
Saturation77%
Lightness39%
Temperature
Warm ← → Cool83% 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#1817af
RGBrgb(24, 23, 175)
HSLhsl(240, 77%, 39%)
CMYKcmyk(86%, 87%, 0%, 31%)
LABlab(23.3 53.3 -76.4)
LCHlch(23.3 93.2 304.9)
OKLCHoklch(0.363 0.221 268.2)
Decimal1578927
Display P3color(display-p3 0.094 0.090 0.686)

Copy-ready code

/* CSS */
color: #1817af;
background-color: #1817af;
/* Tailwind (arbitrary) */
class="text-[#1817af] bg-[#1817af]"
/* SCSS */
$brand: #1817af;
/* SwiftUI */
Color(red: 0.094, green: 0.090, blue: 0.686)
/* Android */
Color.parseColor("#1817af")
/* Flutter */
Color(0xFF1817AF)
/* Python / OpenCV (BGR) */
(175, 23, 24)

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 #1817af · 11.79:1
Use #ffffffAAA at every size.
Aa
White text · 11.79:1 · recommended
AA pass · AA large pass · AAA pass
Aa
Black text · 1.78:1
AA fail · AA large fail · AAA fail
Reading the other direction: #1817af as text scores 11.79:1 on white and 1.78:1 on black.

Accessibility — WCAG contrast

Aa
#1817af on white: 11.79:1
AA ✓ pass · AA-large · AAA
Aa
#1817af on black: 1.78:1
AA ✗ fail · AA-large · AAA
true color
protanopia · #003FB3
deuteranopia · #002FAD
tritanopia · #004B67

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #1817af 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.

#F3F3FC
#E7E7F9
#C8C7F4
#9C9CF2
#6B6AEB
#3A39E5
#1E1CD8
#1817af
#141390
#131268
#0C0B41
Base = 700Lightest = 50 · #F3F3FCDarkest = 950 · #0C0B41
:root {
  --brand-50: #F3F3FC;
  --brand-100: #E7E7F9;
  --brand-200: #C8C7F4;
  --brand-300: #9C9CF2;
  --brand-400: #6B6AEB;
  --brand-500: #3A39E5;
  --brand-600: #1E1CD8;
  --brand-700: #1817af;
  --brand-800: #141390;
  --brand-900: #131268;
  --brand-950: #0C0B41;
  --brand: #1817af;
  --brand-ink: #ffffff;
}

Colors that work with #1817af

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#F4F4FA
Tinted page background
Border#C0C0ED
Hairlines and dividers
Muted text#4B4B9B
Captions on the surface
Accent#B89014
Second voice, not a rival
Dark variant#0F0F71
Hover, pressed, headers
Light variant#E9E8FC
Selected rows, tints
Dark surface#141424
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 #1817af

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

Works well for
  • Body text and links on white
  • 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
  • Text on black or near-black surfaces
  • Full-page backgrounds — tiring over long sessions
  • Black 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#AEAF17
Analogous left#1762AF
Analogous right#6417AF
Split-complement 1#AF6417
Split-complement 2#62AF17
Triadic 1#AF1817
Triadic 2#17AF18
Tetradic#AF1762

RGB percentages

Red9.4%
Green9.0%
Blue68.6%

CMYK percentages

Cyan86.3%
Magenta86.9%
Yellow0.0%
Key (black)31.4%

Color previews

#1817af text on a black background

contrast 1.78:1

Card sample

#1817af text on a white background

contrast 11.79:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #1817af;
Background color
Panel with #1817af background
background-color: #1817af;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #1817af;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(24, 23, 175, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(24, 23, 175, 0.45);
Border & gradient
Gradient panel
border: 3px solid #1817af;
background: linear-gradient(135deg, #1817af, #7D17AF);

Monochromatic scale

Palettes built from #1817af

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.

#1817af 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
ButtonsLinksFocus statesCharts
Print note

Sits outside most CMYK gamuts — expect a duller press result, or specify a spot ink.

#1817af, answered

What color is #1817af?

#1817af is a dark electric blue, closest to Medium Blue (ΔE2000 3.7). It sits at 240° on the hue wheel with 77% saturation and 39% lightness, which reads as cool.

What is the RGB value of #1817af?

rgb(24, 23, 175) — 24 red, 23 green and 175 blue out of 255, or 9.4% / 9% / 68.6% by channel.

Is #1817af a light or a dark color?

It is a dark color. Relative luminance is 0.0390 and perceived brightness is 25%, so white text on it reaches 11.79:1.

Should I use black or white text on #1817af?

White. It scores 11.79:1 against #1817af, versus 1.78:1 for black — AAA at any size.

What is the complementary color of #1817af?

#AEAF17 sits directly opposite on the wheel. Softer options are the split-complements #AF6417 and #62AF17, which give the same contrast with far less vibration.

What colors go well with #1817af?

For interface work: #F4F4FA as the surface, #C0C0ED for borders, #4B4B9B for secondary text, #B89014 as an accent and #0F0F71 for hover and pressed states. For a palette, the analogous pair #1762AF and #6417AF stays calm, while #AEAF17 is the loudest partner.

What is #1817af in CMYK for printing?

cmyk(86%, 87%, 0%, 31%). This is a screen-to-ink approximation — a color this saturated sits outside most CMYK gamuts and will print duller than it looks here.

Is #1817af warm or cool?

Cool — it scores 83 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #5017AF; nudged cooler, #153EB1.

Work with #1817af in the Color Lab