DukeBlue
#00009CBlue family
About DukeBlue
DukeBlue (#00009C) is a dark, vivid blue. Blue is the world's most popular favorite color, associated with trust, calm and depth, and this shade carries that steady, dependable character.
Psychology
Blue lowers stress and is associated with trust, intelligence and reliability. It is the color of stability and competence, which is why so many banks, insurers and technology companies build their brands around it.
Applications
Blue dominates corporate, financial, healthcare and technology design. Light blues feel airy and clean, while deep blues convey authority and luxury. It is also the default for links and primary buttons in countless interfaces.
History
Ultramarine was once made from ground lapis lazuli and was more expensive than gold, reserved for the robes of the Virgin Mary in Renaissance art. Prussian blue and synthetic ultramarine later made blue affordable and ubiquitous.
Meaning
Blue commonly means trust, peace, loyalty and wisdom. In some cultures it is protective, in others it signifies sadness, and it is widely used in flags and institutions to project stability.
Why use this color
Choose blue when you want to build trust, calm and professionalism. It is the safest choice for corporate and financial brands and for interfaces where clarity and reliability matter most.
Accessibility
Against white, #00009C has a 14.2:1 contrast ratio; against black it is 1.5:1. White text on #00009C meets WCAG AA for normal text.
Fun facts
- Blue is the most commonly cited favorite color worldwide.
- Ultramarine was once more expensive than gold because it came from lapis lazuli.
- Blue light has a short wavelength, which is why the sky and distant mountains look blue.
Shades, tints & tones
Variations
Ten lightness steps plus DukeBlue's tints, shades and tones — every swatch copies its hex on click.
Lightness scale
Tints (toward white)
Shades (toward black)
Tones (toward gray)
Color theory
Color harmonies
Proven schemes built around DukeBlue. Each swatch is one click from your clipboard.
Complementary
Analogous
Triadic
Split-complementary
Tetradic
Monochromatic
Accessibility
Blindness simulator
See how DukeBlue is perceived with common types of color vision deficiency.
Normal vision
Standard trichromatic vision, shown for reference.
Protanopia
Red-blind. Reds look darker and can be confused with greens and browns.
Deuteranopia
Green-blind. Greens look muted and can be confused with reds and browns.
Tritanopia
Blue-blind. Blues look greenish and yellows fade toward pink.
Achromatopsia
Complete color blindness. Everything is seen in shades of gray.
WCAG
Contrast checker
How DukeBlue performs against black and white text, with WCAG AA and AAA ratings.
The ratio is identical whether DukeBlue is used as the text or the background.
Open the full checkerReady to use
Color palettes
Curated palettes that put DukeBlue to work, with copy-all support for each.
Complementary
The base color paired with its opposite on the wheel for maximum contrast, plus two neutrals and a soft tint.
Analogous
Neighboring hues on the color wheel create a calm, cohesive scheme with a light tint and a deep shade.
Triadic
Three hues spaced evenly around the wheel for a bold, balanced palette anchored by two neutrals.
Monochromatic
A single hue stepped from light to dark for a clean, elegant and foolproof palette.
DukeBlue (#00009C) is a blue-family color. Use its values, variations, harmonies and palettes above to put it to work in your next design.
Frequently asked questions
DukeBlue is #00009C — rgb(0, 0, 156) / hsl(240, 100%, 31%). DukeBlue (#00009C) is a dark, vivid blue. Blue is the world's most popular favorite color, associated with trust, calm and depth, and this shade carries that steady, dependable character.
Must-know facts
- DukeBlue is one of 355 named colors in the library.
- Its complementary hue sits 180° away on the color wheel: #9e9e00.
Related tools
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