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#175b75

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

RGB
23, 91, 117
HSL
197°, 67%, 28%
CMYK
80, 22, 0, 54
Luminance
0.0895

At a glance

Every number on this page in one read: what #175b75 is made of, how bright it looks, and which way it leans.

Hex
#175b75
Hue
197°
cyan
Saturation
67%
vivid
Lightness
28%
dark
Brightness
46%
HSV value
Perceived
32%
weighted brightness
Luminance
0.0895
WCAG relative
Temperature
Cool
94/100 cool
Color family
Cyan
Tone
Vivid
Best ink
White
7.53:1
Closest name
Dark Slate Gray
ΔE2000 11.8
Where it sits
Hue197° of 360°
Saturation67%
Lightness28%
Temperature
Warm ← → Cool94% 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#175b75
RGBrgb(23, 91, 117)
HSLhsl(197, 67%, 28%)
CMYKcmyk(80%, 22%, 0%, 54%)
LABlab(35.9 -11.1 -20.6)
LCHlch(35.9 23.4 241.8)
OKLCHoklch(0.443 0.077 228.6)
Decimal1530741
Display P3color(display-p3 0.090 0.357 0.459)

Copy-ready code

/* CSS */
color: #175b75;
background-color: #175b75;
/* Tailwind (arbitrary) */
class="text-[#175b75] bg-[#175b75]"
/* SCSS */
$brand: #175b75;
/* SwiftUI */
Color(red: 0.090, green: 0.357, blue: 0.459)
/* Android */
Color.parseColor("#175b75")
/* Flutter */
Color(0xFF175B75)
/* Python / OpenCV (BGR) */
(117, 91, 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 #175b75 · 7.53:1
Use #ffffffAAA at every size.
Aa
White text · 7.53:1 · recommended
AA pass · AA large pass · AAA pass
Aa
Black text · 2.79:1
AA fail · AA large fail · AAA fail
Reading the other direction: #175b75 as text scores 7.53:1 on white and 2.79:1 on black.

Accessibility — WCAG contrast

Aa
#175b75 on white: 7.53:1
AA ✓ pass · AA-large · AAA
Aa
#175b75 on black: 2.79:1
AA ✗ fail · AA-large · AAA
true color
protanopia · #4D5976
deuteranopia · #415075
tritanopia · #006264

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #175b75 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.

#F3F9FB
#E8F3F8
#CAE7F1
#A1D8ED
#72C4E3
#44B0DA
#289FCD
#2285AA
#1B6A88
#175b75
#0F313E
Base = 900Lightest = 50 · #F3F9FBDarkest = 950 · #0F313E
:root {
  --brand-50: #F3F9FB;
  --brand-100: #E8F3F8;
  --brand-200: #CAE7F1;
  --brand-300: #A1D8ED;
  --brand-400: #72C4E3;
  --brand-500: #44B0DA;
  --brand-600: #289FCD;
  --brand-700: #2285AA;
  --brand-800: #1B6A88;
  --brand-900: #175b75;
  --brand-950: #0F313E;
  --brand: #175b75;
  --brand-ink: #ffffff;
}

Colors that work with #175b75

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#F4F9FA
Tinted page background
Border#C0E0ED
Hairlines and dividers
Muted text#4B859B
Captions on the surface
Accent#781714
Second voice, not a rival
Dark variant#15536B
Hover, pressed, headers
Light variant#EAF6FB
Selected rows, tints
Dark surface#142024
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 #175b75

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#753117
Analogous left#177560
Analogous right#172C75
Split-complement 1#75172C
Split-complement 2#756017
Triadic 1#75175B
Triadic 2#5B7517
Tetradic#601775

RGB percentages

Red9.0%
Green35.7%
Blue45.9%

CMYK percentages

Cyan80.3%
Magenta22.2%
Yellow0.0%
Key (black)54.1%

Color previews

#175b75 text on a black background

contrast 2.79:1

Card sample

#175b75 text on a white background

contrast 7.53:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #175b75;
Background color
Panel with #175b75 background
background-color: #175b75;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #175b75;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(23, 91, 117, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(23, 91, 117, 0.45);
Border & gradient
Gradient panel
border: 3px solid #175b75;
background: linear-gradient(135deg, #175b75, #171C75);

Monochromatic scale

Palettes built from #175b75

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.

#175b75 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.

#175b75, answered

What color is #175b75?

#175b75 is a dark vivid cyan, closest to Dark Slate Gray (ΔE2000 11.8). It sits at 197° on the hue wheel with 67% saturation and 28% lightness, which reads as cool.

What is the RGB value of #175b75?

rgb(23, 91, 117) — 23 red, 91 green and 117 blue out of 255, or 9% / 35.7% / 45.9% by channel.

Is #175b75 a light or a dark color?

It is a dark color. Relative luminance is 0.0895 and perceived brightness is 32%, so white text on it reaches 7.53:1.

Should I use black or white text on #175b75?

White. It scores 7.53:1 against #175b75, versus 2.79:1 for black — AAA at any size.

What is the complementary color of #175b75?

#753117 sits directly opposite on the wheel. Softer options are the split-complements #75172C and #756017, which give the same contrast with far less vibration.

What colors go well with #175b75?

For interface work: #F4F9FA as the surface, #C0E0ED for borders, #4B859B for secondary text, #781714 as an accent and #15536B for hover and pressed states. For a palette, the analogous pair #177560 and #172C75 stays calm, while #753117 is the loudest partner.

What is #175b75 in CMYK for printing?

cmyk(80%, 22%, 0%, 54%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #175b75 warm or cool?

Cool — it scores 94 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #17756D; nudged cooler, #164B77.

Work with #175b75 in the Color Lab