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#373c5d

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

RGB
55, 60, 93
HSL
232°, 26%, 29%
CMYK
41, 36, 0, 64
Luminance
0.0483

At a glance

Every number on this page in one read: what #373c5d is made of, how bright it looks, and which way it leans.

Hex
#373c5d
Hue
232°
blue
Saturation
26%
soft
Lightness
29%
dark
Brightness
36%
HSV value
Perceived
25%
weighted brightness
Luminance
0.0483
WCAG relative
Temperature
Cool
78/100 cool
Color family
Blue
Tone
Soft
Best ink
White
10.68:1
Closest name
Dark Slate Blue
ΔE2000 10.2
Where it sits
Hue232° of 360°
Saturation26%
Lightness29%
Temperature
Warm ← → Cool78% 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#373c5d
RGBrgb(55, 60, 93)
HSLhsl(232, 26%, 29%)
CMYKcmyk(41%, 36%, 0%, 64%)
LABlab(26.3 7.3 -20.3)
LCHlch(26.3 21.6 289.7)
OKLCHoklch(0.367 0.057 276.6)
Decimal3619933
Display P3color(display-p3 0.216 0.235 0.365)

Copy-ready code

/* CSS */
color: #373c5d;
background-color: #373c5d;
/* Tailwind (arbitrary) */
class="text-[#373c5d] bg-[#373c5d]"
/* SCSS */
$brand: #373c5d;
/* SwiftUI */
Color(red: 0.216, green: 0.235, blue: 0.365)
/* Android */
Color.parseColor("#373c5d")
/* Flutter */
Color(0xFF373C5D)
/* Python / OpenCV (BGR) */
(93, 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 #373c5d · 10.68:1
Use #ffffffAAA at every size.
Aa
White text · 10.68:1 · recommended
AA pass · AA large pass · AAA pass
Aa
Black text · 1.97:1
AA fail · AA large fail · AAA fail
Reading the other direction: #373c5d as text scores 10.68:1 on white and 1.97:1 on black.

Accessibility — WCAG contrast

Aa
#373c5d on white: 10.68:1
AA ✓ pass · AA-large · AAA
Aa
#373c5d on black: 1.97:1
AA ✗ fail · AA-large · AAA
true color
protanopia · #31405E
deuteranopia · #2F3D5C
tritanopia · #2C4248

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #373c5d 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.

#F6F6F9
#EDEDF3
#D6D8E5
#B8BCD5
#959BC0
#727AAC
#5B639A
#4C5380
#373c5d
#2F334C
#1D202F
Base = 800Lightest = 50 · #F6F6F9Darkest = 950 · #1D202F
:root {
  --brand-50: #F6F6F9;
  --brand-100: #EDEDF3;
  --brand-200: #D6D8E5;
  --brand-300: #B8BCD5;
  --brand-400: #959BC0;
  --brand-500: #727AAC;
  --brand-600: #5B639A;
  --brand-700: #4C5380;
  --brand-800: #373c5d;
  --brand-900: #2F334C;
  --brand-950: #1D202F;
  --brand: #373c5d;
  --brand-ink: #ffffff;
}

Colors that work with #373c5d

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#F5F6F9
Tinted page background
Border#CCCEE1
Hairlines and dividers
Muted text#555D90
Captions on the surface
Accent#604F34
Second voice, not a rival
Dark variant#2F3450
Hover, pressed, headers
Light variant#EFF0F6
Selected rows, tints
Dark surface#151723
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 #373c5d

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#5D5837
Analogous left#374F5D
Analogous right#45375D
Split-complement 1#5D4537
Split-complement 2#4F5D37
Triadic 1#5D373C
Triadic 2#3C5D37
Tetradic#5D374F

RGB percentages

Red21.6%
Green23.5%
Blue36.5%

CMYK percentages

Cyan40.9%
Magenta35.5%
Yellow0.0%
Key (black)63.5%

Color previews

#373c5d text on a black background

contrast 1.97:1

Card sample

#373c5d text on a white background

contrast 10.68:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #373c5d;
Background color
Panel with #373c5d background
background-color: #373c5d;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #373c5d;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(55, 60, 93, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(55, 60, 93, 0.45);
Border & gradient
Gradient panel
border: 3px solid #373c5d;
background: linear-gradient(135deg, #373c5d, #4B375D);

Monochromatic scale

Palettes built from #373c5d

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.

#373c5d 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.

#373c5d, answered

What color is #373c5d?

#373c5d is a dark soft blue, closest to Dark Slate Blue (ΔE2000 10.2). It sits at 232° on the hue wheel with 26% saturation and 29% lightness, which reads as cool.

What is the RGB value of #373c5d?

rgb(55, 60, 93) — 55 red, 60 green and 93 blue out of 255, or 21.6% / 23.5% / 36.5% by channel.

Is #373c5d a light or a dark color?

It is a dark color. Relative luminance is 0.0483 and perceived brightness is 25%, so white text on it reaches 10.68:1.

Should I use black or white text on #373c5d?

White. It scores 10.68:1 against #373c5d, versus 1.97:1 for black — AAA at any size.

What is the complementary color of #373c5d?

#5D5837 sits directly opposite on the wheel. Softer options are the split-complements #5D4537 and #4F5D37, which give the same contrast with far less vibration.

What colors go well with #373c5d?

For interface work: #F5F6F9 as the surface, #CCCEE1 for borders, #555D90 for secondary text, #604F34 as an accent and #2F3450 for hover and pressed states. For a palette, the analogous pair #374F5D and #45375D stays calm, while #5D5837 is the loudest partner.

What is #373c5d in CMYK for printing?

cmyk(41%, 36%, 0%, 64%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #373c5d warm or cool?

Cool — it scores 78 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #40375D; nudged cooler, #35465E.

Work with #373c5d in the Color Lab