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#373c6e

a dark, soft blue · cool · closest name: Dark Slate Blue

RGB
55, 60, 110
HSL
235°, 33%, 32%
CMYK
50, 46, 0, 57
Luminance
0.0517

At a glance

Every number on this page in one read: what #373c6e is made of, how bright it looks, and which way it leans.

Hex
#373c6e
Hue
235°
blue
Saturation
33%
soft
Lightness
32%
dark
Brightness
43%
HSV value
Perceived
26%
weighted brightness
Luminance
0.0517
WCAG relative
Temperature
Cool
85/100 cool
Color family
Blue
Tone
Soft
Best ink
White
10.32:1
Closest name
Dark Slate Blue
ΔE2000 6.4
Where it sits
Hue235° of 360°
Saturation33%
Lightness32%
Temperature
Warm ← → Cool85% 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#373c6e
RGBrgb(55, 60, 110)
HSLhsl(235, 33%, 32%)
CMYKcmyk(50%, 46%, 0%, 57%)
LABlab(27.2 12.9 -29.8)
LCHlch(27.2 32.4 293.4)
OKLCHoklch(0.377 0.085 277.2)
Decimal3619950
Display P3color(display-p3 0.216 0.235 0.431)

Copy-ready code

/* CSS */
color: #373c6e;
background-color: #373c6e;
/* Tailwind (arbitrary) */
class="text-[#373c6e] bg-[#373c6e]"
/* SCSS */
$brand: #373c6e;
/* SwiftUI */
Color(red: 0.216, green: 0.235, blue: 0.431)
/* Android */
Color.parseColor("#373c6e")
/* Flutter */
Color(0xFF373C6E)
/* Python / OpenCV (BGR) */
(110, 60, 55)

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 #373c6e · 10.32:1
Use #ffffffAAA at every size.
Aa
White text · 10.32:1 · recommended
AA pass · AA large pass · AAA pass
Aa
Black text · 2.03:1
AA fail · AA large fail · AAA fail
Reading the other direction: #373c6e as text scores 10.32:1 on white and 2.03:1 on black.

Accessibility — WCAG contrast

Aa
#373c6e on white: 10.32:1
AA ✓ pass · AA-large · AAA
Aa
#373c6e on black: 2.03:1
AA ✗ fail · AA-large · AAA
true color
protanopia · #284370
deuteranopia · #243E6D
tritanopia · #23464F

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #373c6e is pinned to step 800; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F5F6F9
#ECECF4
#D4D6E8
#B4B8DA
#8F94C7
#6970B4
#5259A3
#444A88
#373c6e
#2A2E50
#1B1D32
Base = 800Lightest = 50 · #F5F6F9Darkest = 950 · #1B1D32
:root {
  --brand-50: #F5F6F9;
  --brand-100: #ECECF4;
  --brand-200: #D4D6E8;
  --brand-300: #B4B8DA;
  --brand-400: #8F94C7;
  --brand-500: #6970B4;
  --brand-600: #5259A3;
  --brand-700: #444A88;
  --brand-800: #373c6e;
  --brand-900: #2A2E50;
  --brand-950: #1B1D32;
  --brand: #373c6e;
  --brand-ink: #ffffff;
}

Colors that work with #373c6e

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#F5F5FA
Tinted page background
Border#C9CBE4
Hairlines and dividers
Muted text#4D5499
Captions on the surface
Accent#715C34
Second voice, not a rival
Dark variant#2B2E55
Hover, pressed, headers
Light variant#EEEFF6
Selected rows, tints
Dark surface#141524
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 #373c6e

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
  • 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#6E6937
Analogous left#37586E
Analogous right#4E376E
Split-complement 1#6E4E37
Split-complement 2#586E37
Triadic 1#6E373C
Triadic 2#3C6E37
Tetradic#6E3758

RGB percentages

Red21.6%
Green23.5%
Blue43.1%

CMYK percentages

Cyan50.0%
Magenta45.5%
Yellow0.0%
Key (black)56.9%

Color previews

#373c6e text on a black background

contrast 2.03:1

Card sample

#373c6e text on a white background

contrast 10.32:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #373c6e;
Background color
Panel with #373c6e background
background-color: #373c6e;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #373c6e;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(55, 60, 110, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(55, 60, 110, 0.45);
Border & gradient
Gradient panel
border: 3px solid #373c6e;
background: linear-gradient(135deg, #373c6e, #57376E);

Monochromatic scale

Palettes built from #373c6e

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.

#373c6e 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

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

#373c6e, answered

What color is #373c6e?

#373c6e is a dark soft blue, closest to Dark Slate Blue (ΔE2000 6.4). It sits at 235° on the hue wheel with 33% saturation and 32% lightness, which reads as cool.

What is the RGB value of #373c6e?

rgb(55, 60, 110) — 55 red, 60 green and 110 blue out of 255, or 21.6% / 23.5% / 43.1% by channel.

Is #373c6e a light or a dark color?

It is a dark color. Relative luminance is 0.0517 and perceived brightness is 26%, so white text on it reaches 10.32:1.

Should I use black or white text on #373c6e?

White. It scores 10.32:1 against #373c6e, versus 2.03:1 for black — AAA at any size.

What is the complementary color of #373c6e?

#6E6937 sits directly opposite on the wheel. Softer options are the split-complements #6E4E37 and #586E37, which give the same contrast with far less vibration.

What colors go well with #373c6e?

For interface work: #F5F5FA as the surface, #C9CBE4 for borders, #4D5499 for secondary text, #715C34 as an accent and #2B2E55 for hover and pressed states. For a palette, the analogous pair #37586E and #4E376E stays calm, while #6E6937 is the loudest partner.

What is #373c6e in CMYK for printing?

cmyk(50%, 46%, 0%, 57%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #373c6e warm or cool?

Cool — it scores 85 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #46376E; nudged cooler, #354C70.

Work with #373c6e in the Color Lab