Nautilus

Also known as: Navy Peony, Midnight Sleigh, Madison, Academic Blue

Expect calm and trustworthy associations from Nautilus — a rich blue well suited to corporate branding and SaaS products. Because it leans cool, balancing it with a brown keeps a palette from feeling one-note. On white it reads clearly at 11.17:1 contrast — safe for body text under WCAG AA.

Nautilus color codes

HEX
#273C5A
RGB
rgb(39, 60, 90)
RGBA
rgba(39, 60, 90, 1)
HSL
hsl(215, 40%, 25%)
HSV
hsv(215, 57%, 35%)
CMYK
cmyk(57%, 33%, 0%, 65%)
LAB
lab(24.7 -1.0 -20.9)
OKLCH
oklch(35.3% 0.059 257.3)

Color intelligence

sRGB safe

Displays accurately on every screen and translates well to print.

Temperature

CoolWarm

cool

Nearest standard colors

  • CSS: darkslateblue#483D8B · ΔE 10.8
  • RAL 5003 — Sapphire blue#2A3756 · ΔE 3.2 · 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 Nautilus works

  • Web & UI: Dark enough for body text and icons on white backgrounds — it passes WCAG AA as-is.
  • Interiors: Strong for a whole room, excellent in doses: an accent wall, cabinetry, or a statement chair.
  • Fashion: Wears best as the statement piece — a top, scarf, or shoes — against neutral basics.
  • Branding: Sits in the trust register — a natural primary for finance, health, and B2B brands.
  • Web & UI: A supporting-cast color for UI: chart fills, tags, empty-state illustrations — not text.
  • Branding: A secondary brand color by nature: it supports a stronger primary and shines in illustration.

Copy as — every ecosystem

Tints, shades, and tones of Nautilus

Tints (lighter)

Shades (darker)

Tones (muted)

Color harmonies

Palettes built from Nautilus 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 11.17:1

AA passAAA passAA large pass

Aa — on black

contrast 1.88:1

AA failAAA failAA large fail

Best text color on a Nautilus background: #ffffff

Palettes featuring Nautilus

Nautilus with its complement

Soft neighbors of Nautilus

Nautilus triad

Similar colors

Looking for maximum contrast instead? The complement of Nautilus is closest to Pineapple.

Nautilus FAQs

What color is Nautilus?

Nautilus is a dark blue with the hex code #273C5A. In HSL terms it has a hue of 215°, 40% saturation, and 25% lightness.

What is the hex code for Nautilus?

The hex code for Nautilus is #273C5A. In RGB it's rgb(39, 60, 90), and in CMYK it's cmyk(57%, 33%, 0%, 65%).

What colors go well with Nautilus?

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

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