#397fb6

Boston Blue

Closest match (91% match)

Color formats

RGB

rgb(57, 127, 182)

Red, Green, Blue components

HSL

hsl(206, 52%, 47%)

Hue, Saturation, Lightness

CMYK

cmyk(69, 30, 0, 29)

Print color encoding

Luminance

0.194

Relative luminance

Variations

Shades (Darkening)

Tints (Lightening)

Tones (Reduced saturation)

Harmonies

Click the color slices to copy the code.

Complementary (Opposite)

#397fb6

#b67039

Analogous (Adjacent)

#39b6af

#397fb6

#3940b6

Triadic

#397fb6

#b6397f

#7fb639

Split complementary

#397fb6

#b63940

#b6ae39

Complete conversion table

HEX

#397FB6

RGB

rgb(57,127,182)

RGBA

rgba(57,127,182, 1)

HSL

hsl(206.4,52.3%,46.86%)

OKLCH (Modern CSS)

oklch(0.58 0.11 245.2)

CSS Variable

--color: #397fb6;

Preview

Readability and Typography

Headline Test

This text demonstrates the reading experience on this background color.

Headline Test

This text demonstrates the reading experience on this background color.

UI Component Set

This is an example alert bar using the selected color.

SOLIDSOFTOUTLINE

Product Mockup

4582 •••• •••• 9018

CARDHOLDER

JOHN DOE

VALID

12/28

Mobile application

Customer support

Hi! How can we help you today?

I love this new color! 😍

Data visualization

Weekly growth

+1,240

12.5%

WED

2,450

Contrast

Contrast and readability (WCAG)

On white background

4.30

Small text (14pt)

The quick brown fox jumps over...

AAA

Large text or UI (18pt Bold)

AAA

On black background

4.89

Small text (14pt)

The quick brown fox jumps over...

AAA

Large text or UI (18pt Bold)

AAA

Color blindness simulator

ORIG

SIM

Protanopia (red)

#397fb6#9798b6

ORIG

SIM

Deuteranopia (green)

#397fb6#675fb6

ORIG

SIM

Tritanopia (blue)

#397fb6#3d545e

ORIG

SIM

Monochrome (color blind)

#397fb6#7a7a7a

Mixing guide

How to mix this color using physical paints or printing inks.

MIXING PALETTE

76%

12%

11%

RYB PIGMENTS

Ultramarine blue

Pigment

76%

Cadmium yellow

Pigment

12%

Ivory black

Pigment

11%

Unlike light, mixing paints makes colors darker. This simulation mimics the behavior of physical pigments.

Physical properties

Perceptual and light-related properties derived from the digital color.

Spectral relationship

Blue hue

450–495 nm • closest visible-spectrum range

750 nm

380 nm

Visual temperature

Cool

A perceptual warm–cool classification. Kelvin does not apply to an arbitrary interface color.

Cool

Neutral

Warm

Luminance (brightness)

19.4%

Dark • relative luminance

50%

100%

An RGB color is produced by combined screen light, so this range is a visual comparison rather than an exact physical wavelength.

Gradient gallery

Generate premium CSS backgrounds and textures from your color.

Similar & Related Colors

Mathematically computed harmonies, shades, and similar tones for this color.

Haddock’s Sweater

#277ABA

King Triton

#3C85BE

Warm Spring

#4286BC

Star of Life

#057BC1

Copper

#B67039

Governor Bay

#3940B6

Keppel

#39B6AF

Medium Red Violet

#B6397F

Sushi

#7FB639

Medium Carmine

#B63940

Jordy Blue

#7AB8F3

Orient

#004B7D