Duke Blue (#00009C)

The hex code for Duke Blue is #00009C. It is rgb(0, 0, 156) in RGB, hsl(240, 100%, 31%) in HSL, and about cmyk(100%, 100%, 0%, 39%) in CMYK — a dark blue. White text is the more readable choice on this background.

#00009C

HEX#00009C

RGBrgb(0, 0, 156)

HSLhsl(240, 100%, 31%)

HSVhsv(240, 100%, 61%)

CMYKcmyk(100%, 100%, 0%, 39%)

OKLCHoklch(31.3% 0.217 264.1)

LABlab(15.57% 47.31 -77.61)

LCHlch(15.57% 90.89 301.36)

Colors Closest to Duke Blue

Duke Blue is a registered color name. These are the named colors nearest to it, measured as CIE76 distance in CIELAB — a perceptual scale, so the ordering matches what the eye sees rather than how close the raw RGB numbers happen to sit.

Neon Blue#1B03A3ΔE 2.8 Blue Ribbon#0B10A2ΔE 4.74 Zaffer (Zaffre)#0014A8ΔE 5.52 Blue (Pantone)#0018A8ΔE 7.2 Dark Blue#00008BΔE 7.78 Websafe Indigo#330099ΔE 7.89

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

#00009C Channel Values

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

Model	Channels	Notes
RGB	R 0 · G 0 · B 156	8-bit channels as sent to the display
HSL	H 240° · S 100% · L 31%	Easiest model for building lighter and darker variants
HSV	H 240° · S 100% · V 61%	Matches the picker in most design tools
CMYK	C 100% · M 100% · Y 0% · K 39%	Approximate ink mix; confirm with an ICC profile before printing
Luminance	14.19:1 vs white · 1.48:1 vs black	WCAG 2.2 relative-luminance contrast ratios

Text Contrast & Accessibility

WCAG 2.2 contrast ratios for text on a Duke Blue 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.

TextWhite text14.19:1AA normal ✓AA large ✓AAA normal ✓

TextBlack text1.48:1AA normal ✗AA large ✗AAA normal ✗

Need a specific ratio against another background? Open #00009C in the contrast checker.

Colors That Go With Duke Blue

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

Base

Complementary

Analogous

Analogous

Triadic

Triadic

Split comp.

Split comp.

Tints & Shades of Duke Blue

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

Shades

Want a full 50-950 ramp with semantic roles? Generate design tokens from #00009C.

How Duke Blue 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#00009C

Protanopia#00009C

Protanomaly#00009C

Deuteranopia#00009C

Deuteranomaly#00009C

Tritanopia#003A3A

Tritanomaly#002C6F

Achromatopsia#2B2B2B

Test a full palette in the color blindness simulator.

Using #00009C in Code

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

CSS custom property--duke-blue: #00009C;

CSS backgroundbackground-color: #00009C;

Tailwind configcolors: { 'duke-blue': '#00009C' }

SwiftUIColor(red: 0.000, green: 0.000, blue: 0.612)

Android XML<color name="duke_blue">#00009C</color>

SVG fillfill="#00009C"

More Blue Colors

Duke Blue sits in the bluefamily. These are its neighbours across that family's full range, each with its own breakdown.

00009e 000099 0000b3 000094 0000bd 00008b 0000cc 000080 0000cd 00007a 0000db 000070 00549e 0769a6 161664 224fd8 333366 434c56 5a4fcf 71a6d2 8ba8b7 a7b9f1 c5cbe1 e6e6fa

#00009C Frequently Asked Questions

What is the hex code for Duke Blue?

The hex code for Duke Blue is #00009C. That is rgb(0, 0, 156) in RGB, hsl(240, 100%, 31%) in HSL, and approximately cmyk(100%, 100%, 0%, 39%) in CMYK.

What is the RGB value of #00009C?

#00009C is rgb(0, 0, 156) — red 0, green 0, and blue 156 on the 0-255 scale.

What is the CMYK value of #00009C?

#00009C converts to approximately cmyk(100%, 100%, 0%, 39%). CMYK output is a mathematical approximation for planning; confirm production print colors with your printer and ICC profile.

Should text on #00009C be black or white?

White text is the more readable choice. #00009C scores 14.19:1 against white and 1.48:1 against black, and WCAG 2.2 asks for at least 4.5:1 for normal body text.

Can I write #00009C as a CSS color keyword?

No. #00009C 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 darkblue (#00008B) at a CIE76 distance of 7.78, which is clearly related but distinguishable side by side.

Open Duke Blue in a Tool

Hex to RGB Hex to HSL Hex to CMYK Hex to OKLCH Hex to Pantone Build a palette Make a gradient

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