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#175c55

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

RGB
23, 92, 85
HSL
174°, 60%, 23%
CMYK
75, 0, 8, 64
Luminance
0.0849

At a glance

Every number on this page in one read: what #175c55 is made of, how bright it looks, and which way it leans.

Hex
#175c55
Hue
174°
cyan
Saturation
60%
vivid
Lightness
23%
deep
Brightness
36%
HSV value
Perceived
30%
weighted brightness
Luminance
0.0849
WCAG relative
Temperature
Cool
85/100 cool
Color family
Cyan
Tone
Vivid
Best ink
White
7.78:1
Closest name
Dark Slate Gray
ΔE2000 8.1
Where it sits
Hue174° of 360°
Saturation60%
Lightness23%
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#175c55
RGBrgb(23, 92, 85)
HSLhsl(174, 60%, 23%)
CMYKcmyk(75%, 0%, 8%, 64%)
LABlab(35.0 -22.7 -2.1)
LCHlch(35.0 22.8 185.3)
OKLCHoklch(0.431 0.067 185.1)
Decimal1530965
Display P3color(display-p3 0.090 0.361 0.333)

Copy-ready code

/* CSS */
color: #175c55;
background-color: #175c55;
/* Tailwind (arbitrary) */
class="text-[#175c55] bg-[#175c55]"
/* SCSS */
$brand: #175c55;
/* SwiftUI */
Color(red: 0.090, green: 0.361, blue: 0.333)
/* Android */
Color.parseColor("#175c55")
/* Flutter */
Color(0xFF175C55)
/* Python / OpenCV (BGR) */
(85, 92, 23)

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 #175c55 · 7.78:1
Use #ffffffAAA at every size.
Aa
White text · 7.78:1 · recommended
AA pass · AA large pass · AAA pass
Aa
Black text · 2.70:1
AA fail · AA large fail · AAA fail
Reading the other direction: #175c55 as text scores 7.78:1 on white and 2.70:1 on black.

Accessibility — WCAG contrast

Aa
#175c55 on white: 7.78:1
AA ✓ pass · AA-large · AAA
Aa
#175c55 on black: 2.70:1
AA ✗ fail · AA-large · AAA
true color
protanopia · #575655
deuteranopia · #4D4F56
tritanopia · #005E5A

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #175c55 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.

#F4FBFA
#E9F7F5
#CCEFEC
#A5E9E2
#78DDD3
#4BD2C4
#31C4B5
#29A397
#218379
#175c55
#113B37
Base = 900Lightest = 50 · #F4FBFADarkest = 950 · #113B37
:root {
  --brand-50: #F4FBFA;
  --brand-100: #E9F7F5;
  --brand-200: #CCEFEC;
  --brand-300: #A5E9E2;
  --brand-400: #78DDD3;
  --brand-500: #4BD2C4;
  --brand-600: #31C4B5;
  --brand-700: #29A397;
  --brand-800: #218379;
  --brand-900: #175c55;
  --brand-950: #113B37;
  --brand: #175c55;
  --brand-ink: #ffffff;
}

Colors that work with #175c55

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#F4FAFA
Tinted page background
Border#C0EDE8
Hairlines and dividers
Muted text#4B9B93
Captions on the surface
Accent#5E152E
Second voice, not a rival
Dark variant#1A665E
Hover, pressed, headers
Light variant#EBFAF8
Selected rows, tints
Dark surface#142423
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 #175c55

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
  • Thin strokes and 1px borders — they disappear on light UI
  • 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#5C171E
Analogous left#175C32
Analogous right#17405C
Split-complement 1#5C1740
Split-complement 2#5C3217
Triadic 1#55175C
Triadic 2#5C5517
Tetradic#32175C

RGB percentages

Red9.0%
Green36.1%
Blue33.3%

CMYK percentages

Cyan75.0%
Magenta0.0%
Yellow7.6%
Key (black)63.9%

Color previews

#175c55 text on a black background

contrast 2.70:1

Card sample

#175c55 text on a white background

contrast 7.78:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #175c55;
Background color
Panel with #175c55 background
background-color: #175c55;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #175c55;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(23, 92, 85, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(23, 92, 85, 0.45);
Border & gradient
Gradient panel
border: 3px solid #175c55;
background: linear-gradient(135deg, #175c55, #17355C);

Monochromatic scale

Palettes built from #175c55

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.

#175c55 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.

#175c55, answered

What color is #175c55?

#175c55 is a deep vivid cyan, closest to Dark Slate Gray (ΔE2000 8.1). It sits at 174° on the hue wheel with 60% saturation and 23% lightness, which reads as cool.

What is the RGB value of #175c55?

rgb(23, 92, 85) — 23 red, 92 green and 85 blue out of 255, or 9% / 36.1% / 33.3% by channel.

Is #175c55 a light or a dark color?

It is a dark color. Relative luminance is 0.0849 and perceived brightness is 30%, so white text on it reaches 7.78:1.

Should I use black or white text on #175c55?

White. It scores 7.78:1 against #175c55, versus 2.70:1 for black — AAA at any size.

What is the complementary color of #175c55?

#5C171E sits directly opposite on the wheel. Softer options are the split-complements #5C1740 and #5C3217, which give the same contrast with far less vibration.

What colors go well with #175c55?

For interface work: #F4FAFA as the surface, #C0EDE8 for borders, #4B9B93 for secondary text, #5E152E as an accent and #1A665E for hover and pressed states. For a palette, the analogous pair #175C32 and #17405C stays calm, while #5C171E is the loudest partner.

What is #175c55 in CMYK for printing?

cmyk(75%, 0%, 8%, 64%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #175c55 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 #175C3C; nudged cooler, #164A5D.

Work with #175c55 in the Color Lab