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#0f3bcf

a dark, electric blue · cool · closest name: Blue

RGB
15, 59, 207
HSL
226°, 87%, 44%
CMYK
93, 72, 0, 19
Luminance
0.0773

At a glance

Every number on this page in one read: what #0f3bcf is made of, how bright it looks, and which way it leans.

Hex
#0f3bcf
Hue
226°
blue
Saturation
87%
electric
Lightness
44%
dark
Brightness
81%
HSV value
Perceived
33%
weighted brightness
Luminance
0.0773
WCAG relative
Temperature
Cool
91/100 cool
Color family
Blue
Tone
Electric
Best ink
White
8.25:1
Closest name
Blue
ΔE2000 8.4
Where it sits
Hue226° of 360°
Saturation87%
Lightness44%
Temperature
Warm ← → Cool91% 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#0f3bcf
RGBrgb(15, 59, 207)
HSLhsl(226, 87%, 44%)
CMYKcmyk(93%, 72%, 0%, 19%)
LABlab(33.4 44.7 -78.6)
LCHlch(33.4 90.4 299.6)
OKLCHoklch(0.444 0.229 264.6)
Decimal998351
Display P3color(display-p3 0.059 0.231 0.812)

Copy-ready code

/* CSS */
color: #0f3bcf;
background-color: #0f3bcf;
/* Tailwind (arbitrary) */
class="text-[#0f3bcf] bg-[#0f3bcf]"
/* SCSS */
$brand: #0f3bcf;
/* SwiftUI */
Color(red: 0.059, green: 0.231, blue: 0.812)
/* Android */
Color.parseColor("#0f3bcf")
/* Flutter */
Color(0xFF0F3BCF)
/* Python / OpenCV (BGR) */
(207, 59, 15)

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 #0f3bcf · 8.25:1
Use #ffffffAAA at every size.
Aa
White text · 8.25:1 · recommended
AA pass · AA large pass · AAA pass
Aa
Black text · 2.55:1
AA fail · AA large fail · AAA fail
Reading the other direction: #0f3bcf as text scores 8.25:1 on white and 2.55:1 on black.

Accessibility — WCAG contrast

Aa
#0f3bcf on white: 8.25:1
AA ✓ pass · AA-large · AAA
Aa
#0f3bcf on black: 2.55:1
AA ✗ fail · AA-large · AAA
true color
protanopia · #0058D3
deuteranopia · #0045CC
tritanopia · #006681

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #0f3bcf is pinned to step 700; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F2F5FD
#E5EAFA
#C4D0F7
#96ADF7
#6283F4
#2E5AF0
#1141E4
#0f3bcf
#0B2B98
#0C236E
#081645
Base = 700Lightest = 50 · #F2F5FDDarkest = 950 · #081645
:root {
  --brand-50: #F2F5FD;
  --brand-100: #E5EAFA;
  --brand-200: #C4D0F7;
  --brand-300: #96ADF7;
  --brand-400: #6283F4;
  --brand-500: #2E5AF0;
  --brand-600: #1141E4;
  --brand-700: #0f3bcf;
  --brand-800: #0B2B98;
  --brand-900: #0C236E;
  --brand-950: #081645;
  --brand: #0f3bcf;
  --brand-ink: #ffffff;
}

Colors that work with #0f3bcf

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#F4F6FA
Tinted page background
Border#C0CAED
Hairlines and dividers
Muted text#4B5D9B
Captions on the surface
Accent#D3730B
Second voice, not a rival
Dark variant#092277
Hover, pressed, headers
Light variant#E7ECFD
Selected rows, tints
Dark surface#141724
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 #0f3bcf

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
  • 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#CFA30F
Analogous left#0F9BCF
Analogous right#430FCF
Split-complement 1#CF430F
Split-complement 2#9BCF0F
Triadic 1#CF0F3B
Triadic 2#3BCF0F
Tetradic#CF0F9B

RGB percentages

Red5.9%
Green23.1%
Blue81.2%

CMYK percentages

Cyan92.8%
Magenta71.5%
Yellow0.0%
Key (black)18.8%

Color previews

#0f3bcf text on a black background

contrast 2.55:1

Card sample

#0f3bcf text on a white background

contrast 8.25:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #0f3bcf;
Background color
Panel with #0f3bcf background
background-color: #0f3bcf;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #0f3bcf;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(15, 59, 207, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(15, 59, 207, 0.45);
Border & gradient
Gradient panel
border: 3px solid #0f3bcf;
background: linear-gradient(135deg, #0f3bcf, #630FCF);

Monochromatic scale

Palettes built from #0f3bcf

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.

#0f3bcf 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

Sits outside most CMYK gamuts — expect a duller press result, or specify a spot ink.

#0f3bcf, answered

What color is #0f3bcf?

#0f3bcf is a dark electric blue, closest to Blue (ΔE2000 8.4). It sits at 226° on the hue wheel with 87% saturation and 44% lightness, which reads as cool.

What is the RGB value of #0f3bcf?

rgb(15, 59, 207) — 15 red, 59 green and 207 blue out of 255, or 5.9% / 23.1% / 81.2% by channel.

Is #0f3bcf a light or a dark color?

It is a dark color. Relative luminance is 0.0773 and perceived brightness is 33%, so white text on it reaches 8.25:1.

Should I use black or white text on #0f3bcf?

White. It scores 8.25:1 against #0f3bcf, versus 2.55:1 for black — AAA at any size.

What is the complementary color of #0f3bcf?

#CFA30F sits directly opposite on the wheel. Softer options are the split-complements #CF430F and #9BCF0F, which give the same contrast with far less vibration.

What colors go well with #0f3bcf?

For interface work: #F4F6FA as the surface, #C0CAED for borders, #4B5D9B for secondary text, #D3730B as an accent and #092277 for hover and pressed states. For a palette, the analogous pair #0F9BCF and #430FCF stays calm, while #CFA30F is the loudest partner.

What is #0f3bcf in CMYK for printing?

cmyk(93%, 72%, 0%, 19%). This is a screen-to-ink approximation — a color this saturated sits outside most CMYK gamuts and will print duller than it looks here.

Is #0f3bcf warm or cool?

Cool — it scores 91 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #2A0FCF; nudged cooler, #0D51D1.

Work with #0f3bcf in the Color Lab