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#307df1

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

RGB
48, 125, 241
HSL
216°, 87%, 57%
CMYK
80, 48, 0, 6
Luminance
0.2165

At a glance

Every number on this page in one read: what #307df1 is made of, how bright it looks, and which way it leans.

Hex
#307df1
Hue
216°
blue
Saturation
87%
electric
Lightness
57%
balanced
Brightness
95%
HSV value
Perceived
50%
weighted brightness
Luminance
0.2165
WCAG relative
Temperature
Cool
97/100 cool
Color family
Blue
Tone
Electric
Best ink
Black
5.33:1
Closest name
Steel Blue
ΔE2000 6.5
Where it sits
Hue216° of 360°
Saturation87%
Lightness57%
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#307df1
RGBrgb(48, 125, 241)
HSLhsl(216, 87%, 57%)
CMYKcmyk(80%, 48%, 0%, 6%)
LABlab(53.6 17.7 -64.9)
LCHlch(53.6 67.2 285.2)
OKLCHoklch(0.606 0.190 258.9)
Decimal3177969
Display P3color(display-p3 0.188 0.490 0.945)

Copy-ready code

/* CSS */
color: #307df1;
background-color: #307df1;
/* Tailwind (arbitrary) */
class="text-[#307df1] bg-[#307df1]"
/* SCSS */
$brand: #307df1;
/* SwiftUI */
Color(red: 0.188, green: 0.490, blue: 0.945)
/* Android */
Color.parseColor("#307df1")
/* Flutter */
Color(0xFF307DF1)
/* Python / OpenCV (BGR) */
(241, 125, 48)

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 #307df1 · 5.33:1
Use #000000AA at every size, AAA for large text only.
Aa
White text · 3.94:1
AA fail · AA large pass · AAA fail
Aa
Black text · 5.33:1 · recommended
AA pass · AA large pass · AAA fail
Reading the other direction: #307df1 as text scores 3.94:1 on white and 5.33:1 on black.

Accessibility — WCAG contrast

Aa
#307df1 on white: 3.94:1
AA ✗ fail · AA-large · AAA
Aa
#307df1 on black: 5.33:1
AA ✓ pass · AA-large · AAA
true color
protanopia · #3889F5
deuteranopia · #0078EF
tritanopia · #0099AB

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #307df1 is pinned to step 500; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F2F6FD
#E5EEFA
#C4D9F7
#96BDF8
#619CF4
#307df1
#1065E5
#0D54BF
#0A4399
#0C336E
#082045
Base = 500Lightest = 50 · #F2F6FDDarkest = 950 · #082045
:root {
  --brand-50: #F2F6FD;
  --brand-100: #E5EEFA;
  --brand-200: #C4D9F7;
  --brand-300: #96BDF8;
  --brand-400: #619CF4;
  --brand-500: #307df1;
  --brand-600: #1065E5;
  --brand-700: #0D54BF;
  --brand-800: #0A4399;
  --brand-900: #0C336E;
  --brand-950: #082045;
  --brand: #307df1;
  --brand-ink: #000000;
}

Colors that work with #307df1

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#F4F7FA
Tinted page background
Border#C0D2ED
Hairlines and dividers
Muted text#4B6B9B
Captions on the surface
Accent#C34B09
Second voice, not a rival
Dark variant#083477
Hover, pressed, headers
Light variant#E7F0FD
Selected rows, tints
Dark surface#141A24
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 #307df1

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#F1A430
Analogous left#30DDF1
Analogous right#4430F1
Split-complement 1#F14430
Split-complement 2#DDF130
Triadic 1#F1307D
Triadic 2#7DF130
Tetradic#F130DD

RGB percentages

Red18.8%
Green49.0%
Blue94.5%

CMYK percentages

Cyan80.1%
Magenta48.1%
Yellow0.0%
Key (black)5.5%

Color previews

#307df1 text on a black background

contrast 5.33:1

Card sample

#307df1 text on a white background

contrast 3.94:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #307df1;
Background color
Panel with #307df1 background
background-color: #307df1;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #307df1;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(48, 125, 241, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(48, 125, 241, 0.45);
Border & gradient
Gradient panel
border: 3px solid #307df1;
background: linear-gradient(135deg, #307df1, #6430F1);

Monochromatic scale

Palettes built from #307df1

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.

#307df1 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.

#307df1, answered

What color is #307df1?

#307df1 is a balanced electric blue, closest to Steel Blue (ΔE2000 6.5). It sits at 216° on the hue wheel with 87% saturation and 57% lightness, which reads as cool.

What is the RGB value of #307df1?

rgb(48, 125, 241) — 48 red, 125 green and 241 blue out of 255, or 18.8% / 49% / 94.5% by channel.

Is #307df1 a light or a dark color?

It is a mid-tone. Relative luminance is 0.2165 and perceived brightness is 50%, so black text on it reaches 5.33:1.

Should I use black or white text on #307df1?

Black. It scores 5.33:1 against #307df1, versus 3.94:1 for white — AA at any size.

What is the complementary color of #307df1?

#F1A430 sits directly opposite on the wheel. Softer options are the split-complements #F14430 and #DDF130, which give the same contrast with far less vibration.

What colors go well with #307df1?

For interface work: #F4F7FA as the surface, #C0D2ED for borders, #4B6B9B for secondary text, #C34B09 as an accent and #083477 for hover and pressed states. For a palette, the analogous pair #30DDF1 and #4430F1 stays calm, while #F1A430 is the loudest partner.

What is #307df1 in CMYK for printing?

cmyk(80%, 48%, 0%, 6%). 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 #307df1 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 #3036F1; nudged cooler, #1676F2.

Work with #307df1 in the Color Lab