Blue

Also known as: Royal Blue Tang, Graphical 80’s Sky, Primary Blue, Blue Pencil

A vivid blue with a calm and trustworthy character, Blue works beautifully for finance apps and trust-driven interfaces. Match it with brown accents when the design calls for energy over calm. On white it reads clearly at 8.59:1 contrast — safe for body text under WCAG AA.

Blue color codes

HEX
#0000FF
RGB
rgb(0, 0, 255)
RGBA
rgba(0, 0, 255, 1)
HSL
hsl(240, 100%, 50%)
HSV
hsv(240, 100%, 100%)
CMYK
cmyk(100%, 100%, 0%, 0%)
LAB
lab(29.6 68.3 -112.0)
OKLCH
oklch(45.2% 0.313 264.1)

Color intelligence

sRGB safeShifts in CMYK print

Displays accurately on every screen. Vivid colors like this typically lose some intensity in CMYK print — request a physical proof for brand-critical work.

Temperature

CoolWarm

cool

Nearest standard colors

  • CSS: blue#0000FF · ΔE 0.0
  • RAL 5002 — Ultramarine blue#2B2C7C · ΔE 16.6 · approximate

RAL values are widely published approximations of the physical standard. For Pantone-adjacent workflows, match by eye against a physical fan deck — Pantone's values are proprietary and device-dependent, so we don't print lookups.

Where Blue works

  • Web & UI: Use it directly for text on light surfaces; it clears AA contrast without adjustment.
  • Interiors: Use it where you want the eye to land — front door, built-ins, or one bold wall.
  • Fashion: One garment in this color carries an outfit; two starts to compete.
  • Branding: The safest brand-primary family there is; differentiate with an unexpected accent.
  • Web & UI: Reads as an interactive accent: fills, hovers, focus rings. Keep body text in a darker neutral.
  • Branding: Best in a brand's supporting palette — packaging interiors, patterns, campaign accents.

Copy as — every ecosystem

Tints, shades, and tones of Blue

Tints (lighter)

Shades (darker)

Tones (muted)

Color harmonies

Palettes built from Blue by rotating its hue in OKLCH space. Click any swatch to copy its hex code.

Complementary

Analogous

Triadic

Split-complementary

Tetradic

Monochromatic

Contrast & accessibility

Aa — on white

contrast 8.59:1

AA passAAA passAA large pass

Aa — on black

contrast 2.44:1

AA failAAA failAA large fail

Best text color on a Blue background: #ffffff

Palettes featuring Blue

Blue with its complement

Soft neighbors of Blue

Blue triad

Similar colors

Looking for maximum contrast instead? The complement of Blue is closest to Olivary.

Blue FAQs

What color is Blue?

Blue is a medium blue with the hex code #0000FF. In HSL terms it has a hue of 240°, 100% saturation, and 50% lightness.

What is the hex code for Blue?

The hex code for Blue is #0000FF. In RGB it's rgb(0, 0, 255), and in CMYK it's cmyk(100%, 100%, 0%, 0%).

What colors go well with Blue?

Blue pairs naturally with brown tones from its complementary harmony. Its own tints and shades always work as a monochrome scheme.

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