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#3f7dfe

a balanced, electric blue · cool · closest name: Cornflower Blue

RGB
63, 125, 254
HSL
221°, 99%, 62%
CMYK
75, 51, 0, 0
Luminance
0.2288

At a glance

Every number on this page in one read: what #3f7dfe is made of, how bright it looks, and which way it leans.

Hex
#3f7dfe
Hue
221°
blue
Saturation
99%
electric
Lightness
62%
balanced
Brightness
100%
HSV value
Perceived
52%
weighted brightness
Luminance
0.2288
WCAG relative
Temperature
Cool
94/100 cool
Color family
Blue
Tone
Electric
Best ink
Black
5.58:1
Closest name
Cornflower Blue
ΔE2000 7.5
Where it sits
Hue221° of 360°
Saturation99%
Lightness62%
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#3f7dfe
RGBrgb(63, 125, 254)
HSLhsl(221, 99%, 62%)
CMYKcmyk(75%, 51%, 0%, 0%)
LABlab(55.0 24.0 -69.9)
LCHlch(55.0 73.9 288.9)
OKLCHoklch(0.620 0.203 262.7)
Decimal4161022
Display P3color(display-p3 0.247 0.490 0.996)

Copy-ready code

/* CSS */
color: #3f7dfe;
background-color: #3f7dfe;
/* Tailwind (arbitrary) */
class="text-[#3f7dfe] bg-[#3f7dfe]"
/* SCSS */
$brand: #3f7dfe;
/* SwiftUI */
Color(red: 0.247, green: 0.490, blue: 0.996)
/* Android */
Color.parseColor("#3f7dfe")
/* Flutter */
Color(0xFF3F7DFE)
/* Python / OpenCV (BGR) */
(254, 125, 63)

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 #3f7dfe · 5.58:1
Use #000000AA at every size, AAA for large text only.
Aa
White text · 3.77:1
AA fail · AA large pass · AAA fail
Aa
Black text · 5.58:1 · recommended
AA pass · AA large pass · AAA fail
Reading the other direction: #3f7dfe as text scores 3.77:1 on white and 5.58:1 on black.

Accessibility — WCAG contrast

Aa
#3f7dfe on white: 3.77:1
AA ✗ fail · AA-large · AAA
Aa
#3f7dfe on black: 5.58:1
AA ✓ pass · AA-large · AAA
true color
protanopia · #278DFF
deuteranopia · #007BFB
tritanopia · #009CB2

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #3f7dfe is pinned to step 400; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F1F5FE
#E3EBFC
#C0D4FB
#8FB3FE
#3f7dfe
#2068FE
#0150F4
#0143CB
#0135A2
#052A75
#031A49
Base = 400Lightest = 50 · #F1F5FEDarkest = 950 · #031A49
:root {
  --brand-50: #F1F5FE;
  --brand-100: #E3EBFC;
  --brand-200: #C0D4FB;
  --brand-300: #8FB3FE;
  --brand-400: #3f7dfe;
  --brand-500: #2068FE;
  --brand-600: #0150F4;
  --brand-700: #0143CB;
  --brand-800: #0135A2;
  --brand-900: #052A75;
  --brand-950: #031A49;
  --brand: #3f7dfe;
  --brand-ink: #000000;
}

Colors that work with #3f7dfe

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#F4F6FA
Tinted page background
Border#C0CEED
Hairlines and dividers
Muted text#4B659B
Captions on the surface
Accent#CC5700
Second voice, not a rival
Dark variant#012A7F
Hover, pressed, headers
Light variant#E6EEFF
Selected rows, tints
Dark surface#141924
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 #3f7dfe

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
  • Brand accents, badges and data highlights
Use with care
  • Small text on white — under 4.5:1
  • Full-page backgrounds — tiring over long sessions
  • 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#FEC03F
Analogous left#3FDDFE
Analogous right#613FFE
Split-complement 1#FE613F
Split-complement 2#DDFE3F
Triadic 1#FE3F7D
Triadic 2#7DFE3F
Tetradic#FE3FDD

RGB percentages

Red24.7%
Green49.0%
Blue99.6%

CMYK percentages

Cyan75.2%
Magenta50.8%
Yellow0.0%
Key (black)0.4%

Color previews

#3f7dfe text on a black background

contrast 5.58:1

Card sample

#3f7dfe text on a white background

contrast 3.77:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #3f7dfe;
Background color
Panel with #3f7dfe background
background-color: #3f7dfe;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #3f7dfe;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(63, 125, 254, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(63, 125, 254, 0.45);
Border & gradient
Gradient panel
border: 3px solid #3f7dfe;
background: linear-gradient(135deg, #3f7dfe, #803FFE);

Monochromatic scale

Palettes built from #3f7dfe

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.

#3f7dfe 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.

#3f7dfe, answered

What color is #3f7dfe?

#3f7dfe is a balanced electric blue, closest to Cornflower Blue (ΔE2000 7.5). It sits at 221° on the hue wheel with 99% saturation and 62% lightness, which reads as cool.

What is the RGB value of #3f7dfe?

rgb(63, 125, 254) — 63 red, 125 green and 254 blue out of 255, or 24.7% / 49% / 99.6% by channel.

Is #3f7dfe a light or a dark color?

It is a mid-tone. Relative luminance is 0.2288 and perceived brightness is 52%, so black text on it reaches 5.58:1.

Should I use black or white text on #3f7dfe?

Black. It scores 5.58:1 against #3f7dfe, versus 3.77:1 for white — AA at any size.

What is the complementary color of #3f7dfe?

#FEC03F sits directly opposite on the wheel. Softer options are the split-complements #FE613F and #DDFE3F, which give the same contrast with far less vibration.

What colors go well with #3f7dfe?

For interface work: #F4F6FA as the surface, #C0CEED for borders, #4B659B for secondary text, #CC5700 as an accent and #012A7F for hover and pressed states. For a palette, the analogous pair #3FDDFE and #613FFE stays calm, while #FEC03F is the loudest partner.

What is #3f7dfe in CMYK for printing?

cmyk(75%, 51%, 0%, 0%). 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 #3f7dfe 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 #473FFE; nudged cooler, #257CFF.

Work with #3f7dfe in the Color Lab