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#357dac

a dark, vivid blue · cool · closest name: Steel Blue

RGB
53, 125, 172
HSL
204°, 53%, 44%
CMYK
69, 27, 0, 33
Luminance
0.1840

At a glance

Every number on this page in one read: what #357dac is made of, how bright it looks, and which way it leans.

Hex
#357dac
Hue
204°
blue
Saturation
53%
vivid
Lightness
44%
dark
Brightness
67%
HSV value
Perceived
45%
weighted brightness
Luminance
0.1840
WCAG relative
Temperature
Cool
97/100 cool
Color family
Blue
Tone
Vivid
Best ink
Black
4.68:1
Closest name
Steel Blue
ΔE2000 3.1
Where it sits
Hue204° of 360°
Saturation53%
Lightness44%
Temperature
Warm ← → Cool97% 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#357dac
RGBrgb(53, 125, 172)
HSLhsl(204, 53%, 44%)
CMYKcmyk(69%, 27%, 0%, 33%)
LABlab(50.0 -6.9 -31.5)
LCHlch(50.0 32.3 257.6)
OKLCHoklch(0.565 0.102 240.6)
Decimal3505580
Display P3color(display-p3 0.208 0.490 0.675)

Copy-ready code

/* CSS */
color: #357dac;
background-color: #357dac;
/* Tailwind (arbitrary) */
class="text-[#357dac] bg-[#357dac]"
/* SCSS */
$brand: #357dac;
/* SwiftUI */
Color(red: 0.208, green: 0.490, blue: 0.675)
/* Android */
Color.parseColor("#357dac")
/* Flutter */
Color(0xFF357DAC)
/* Python / OpenCV (BGR) */
(172, 125, 53)

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#000000 on #357dac · 4.68:1
Use #000000AA at every size, AAA for large text only.
Aa
White text · 4.49:1
AA fail · AA large pass · AAA fail
Aa
Black text · 4.68:1 · recommended
AA pass · AA large pass · AAA fail
Reading the other direction: #357dac as text scores 4.49:1 on white and 4.68:1 on black.

Accessibility — WCAG contrast

Aa
#357dac on white: 4.49:1
AA ✗ fail · AA-large · AAA
Aa
#357dac on black: 4.68:1
AA ✓ pass · AA-large · AAA
true color
protanopia · #677DAE
deuteranopia · #5772AB
tritanopia · #00898D

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #357dac is pinned to step 600; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F4F8FB
#E9F1F6
#CEE1ED
#A9CDE5
#7EB4D7
#539BCA
#357dac
#30719C
#265B7D
#1F435B
#142A39
Base = 600Lightest = 50 · #F4F8FBDarkest = 950 · #142A39
:root {
  --brand-50: #F4F8FB;
  --brand-100: #E9F1F6;
  --brand-200: #CEE1ED;
  --brand-300: #A9CDE5;
  --brand-400: #7EB4D7;
  --brand-500: #539BCA;
  --brand-600: #357dac;
  --brand-700: #30719C;
  --brand-800: #265B7D;
  --brand-900: #1F435B;
  --brand-950: #142A39;
  --brand: #357dac;
  --brand-ink: #000000;
}

Colors that work with #357dac

Not a palette — a role sheet. Each swatch answers one question you will hit while building the component.

Text on it#000000
Black wins here
Surface#F4F8FA
Tinted page background
Border#C1DBEC
Hairlines and dividers
Muted text#4B7B9B
Captions on the surface
Accent#B04330
Second voice, not a rival
Dark variant#1E4761
Hover, pressed, headers
Light variant#ECF4F9
Selected rows, tints
Dark surface#141E24
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 #357dac

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

Works well for
  • Headings from 24px up on white
  • Text and icons on dark surfaces
  • 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
  • Small text on white — under 4.5:1
  • 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#AC6435
Analogous left#35AC9F
Analogous right#3541AC
Split-complement 1#AC3541
Split-complement 2#AC9F35
Triadic 1#AC357D
Triadic 2#7DAC35
Tetradic#9F35AC

RGB percentages

Red20.8%
Green49.0%
Blue67.5%

CMYK percentages

Cyan69.2%
Magenta27.3%
Yellow0.0%
Key (black)32.5%

Color previews

#357dac text on a black background

contrast 4.68:1

Card sample

#357dac text on a white background

contrast 4.49:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #357dac;
Background color
Panel with #357dac background
background-color: #357dac;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #357dac;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(53, 125, 172, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(53, 125, 172, 0.45);
Border & gradient
Gradient panel
border: 3px solid #357dac;
background: linear-gradient(135deg, #357dac, #3C35AC);

Monochromatic scale

Palettes built from #357dac

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.

#357dac 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.

#357dac, answered

What color is #357dac?

#357dac is a dark vivid blue, closest to Steel Blue (ΔE2000 3.1). It sits at 204° on the hue wheel with 53% saturation and 44% lightness, which reads as cool.

What is the RGB value of #357dac?

rgb(53, 125, 172) — 53 red, 125 green and 172 blue out of 255, or 20.8% / 49% / 67.5% by channel.

Is #357dac a light or a dark color?

It is a mid-tone. Relative luminance is 0.1840 and perceived brightness is 45%, so black text on it reaches 4.68:1.

Should I use black or white text on #357dac?

Black. It scores 4.68:1 against #357dac, versus 4.49:1 for white — AA at any size.

What is the complementary color of #357dac?

#AC6435 sits directly opposite on the wheel. Softer options are the split-complements #AC3541 and #AC9F35, which give the same contrast with far less vibration.

What colors go well with #357dac?

For interface work: #F4F8FA as the surface, #C1DBEC for borders, #4B7B9B for secondary text, #B04330 as an accent and #1E4761 for hover and pressed states. For a palette, the analogous pair #35AC9F and #3541AC stays calm, while #AC6435 is the loudest partner.

What is #357dac in CMYK for printing?

cmyk(69%, 27%, 0%, 33%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #357dac warm or cool?

Cool — it scores 97 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #35A9AC; nudged cooler, #2D669A.

Work with #357dac in the Color Lab