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#3781A9 Color

#3781A9 is rgb(55, 129, 169) in RGB, hsl(201, 51%, 44%) in HSL, and about cmyk(67%, 24%, 0%, 34%) in CMYK. It has no registered color name of its own — the closest is Cerulean (#007BA7), clearly related but distinguishable side by side at ΔE 5.69. Black text is the more readable choice on this background.

#3781A9
HEX#3781A9
RGBrgb(55, 129, 169)
HSLhsl(201, 51%, 44%)
HSVhsv(201, 67%, 66%)
CMYKcmyk(67%, 24%, 0%, 34%)
OKLCHoklch(57.4% 0.095 235.5)
LABlab(50.68% -13.82 -28.60)
LCHlch(50.68% 31.76 244.21)

What #3781A9 Is Called

Most hex codes have no name: there are 16.7 million of them and a few thousand registered names. These are the named colors nearest to #3781A9, ordered by CIE76 distance in CIELAB. Anything under about ΔE 2 is a difference most people cannot see.

Cerulean#007BA7ΔE 5.69Steel Blue#4682B4ΔE 7.03Blue (NCS)#0087BDΔE 9.45Air Force Blue#5D8AA8ΔE 9.65Sea Blue#006994ΔE 9.96Silver Lake Blue#5D89BAΔE 10.26

Browse the full index of named colors A-Z or every blue in the library.

#3781A9 Channel Values

How #3781A9 breaks down in each color model. Hue is measured in degrees around the color wheel; saturation, lightness, and the CMYK inks are percentages.

ModelChannelsNotes
RGBR 55 · G 129 · B 1698-bit channels as sent to the display
HSLH 201° · S 51% · L 44%Easiest model for building lighter and darker variants
HSVH 201° · S 67% · V 66%Matches the picker in most design tools
CMYKC 67% · M 24% · Y 0% · K 34%Approximate ink mix; confirm with an ICC profile before printing
Luminance4.31:1 vs white · 4.88:1 vs blackWCAG 2.2 relative-luminance contrast ratios

Text Contrast & Accessibility

WCAG 2.2 contrast ratios for text on a #3781A9 background. AA requires 4.5:1 for normal text and 3:1 for large text; AAA requires 7:1. Contrast is one check, not a full accessibility review.

Fails AAWhite text4.31:1AA normal AA large AAA normal
TextBlack text4.88:1AA normal AA large AAA normal

Need a specific ratio against another background? Open #3781A9 in the contrast checker.

Colors That Go With #3781A9

Pairings derived from color-wheel relationships. The complementary color sits opposite #3781A9; analogous colors sit beside it; triadic and split-complementary sets spread evenly around the wheel. Select any swatch for its own breakdown.

Base
#3781A9
Complementary
#A95F37
Analogous
#37A998
Analogous
#3748A9
Triadic
#A93781
Triadic
#81A937
Split comp.
#A93748
Split comp.
#A99837

Tints & Shades of #3781A9

Lighter tints and darker shades built by moving the lightness channel while holding hue and saturation, which is what you want for hover states, backgrounds, and text variants.

Tints

#4697C3
#61A6CC
#80B8D6
#9FC9E0
#BEDAEA
#D8E9F3

Shades

#2F7092
#29617F
#224F68
#1A3E51
#132C3A
#0C1D27

Want a full 50-950 ramp with semantic roles? Generate design tokens from #3781A9.

How #3781A9 Looks with Color Vision Deficiency

Simulated with the Viénot, Brettel & Mollon LMS projection model. Anomalous types are rendered as partial versions of the matching dichromacy, which is an approximation rather than a per-person clinical model.

Typical#3781A9
Protanopia#7878A9
Protanomaly#647CA9
Deuteranopia#6F6FAA
Deuteranomaly#5E77AA
Tritanopia#228787
Tritanomaly#2B8596
Achromatopsia#7A7A7A

Test a full palette in the color blindness simulator.

Using #3781A9 in Code

Copy-ready declarations for the places this color usually ends up.

CSS custom property--color-3781a9: #3781A9;
CSS backgroundbackground-color: #3781A9;
Tailwind configcolors: { 'color-3781a9': '#3781A9' }
SwiftUIColor(red: 0.216, green: 0.506, blue: 0.663)
Android XML<color name="color_3781a9">#3781A9</color>
SVG fillfill="#3781A9"

More Blue Colors

#3781A9 sits in the blue family. These are its neighbours across that family's full range, each with its own breakdown.

000024fafaff00002ef9fafb000033f8fafc000038f8f8ff000042f5faff000047f5f5ff002147007dfa0f52ba1c39bb2a3439372aac4e3cc364609a7abdff979aaab8dbffd6d6ff

#3781A9 Frequently Asked Questions

What color is #3781A9?

#3781A9 is a mid-tone blue — rgb(55, 129, 169) in RGB and hsl(201, 51%, 44%) in HSL. It carries no registered color name of its own; the closest named color is Cerulean (#007BA7), which is clearly related but distinguishable side by side at a CIE76 distance of 5.69.

What is the RGB value of #3781A9?

#3781A9 is rgb(55, 129, 169) — red 55, green 129, and blue 169 on the 0-255 scale.

What is the CMYK value of #3781A9?

#3781A9 converts to approximately cmyk(67%, 24%, 0%, 34%). CMYK output is a mathematical approximation for planning; confirm production print colors with your printer and ICC profile.

Should text on #3781A9 be black or white?

Black text is the more readable choice. #3781A9 scores 4.31:1 against white and 4.88:1 against black, and WCAG 2.2 asks for at least 4.5:1 for normal body text.

Can I write #3781A9 as a CSS color keyword?

No. #3781A9 is not one of the CSS color keywords, so it has to be written as a hex, rgb() or hsl() value. The closest keyword is steelblue (#4682B4) at a CIE76 distance of 7.03, which is clearly related but distinguishable side by side.

Open #3781A9 in a Tool

Hex to RGBHex to HSLHex to CMYKHex to OKLCHHex to PantoneBuild a paletteMake a gradient

Keep exploring: every blue in the color library, the guide to shades of blue, or the full color library.