Dark Blue

#315b7d

A blue that is nearly neutral — the hue shows only against a true grey. It is mid — the hardest range to put text on, either colour struggles.

Hex

#315b7d

RGB

49, 91, 125

OKLCh

45.6% 0.073 244.8°

CIELAB (D50)

36.8, -6.8, -24.0

What is true of this colour, and of no other

  • 8 other named colours sit within ΔE00 2 of it.
  • It uses 64% of the chroma sRGB can show at this lightness and hue.
  • As text on white it measures APCA Lc 84.8; on black, Lc -17.2. The sign is the polarity, which the WCAG ratio discards.
  • Built into an eleven-step scale, 10 of the 10 adjacent pairs stay ΔE00 2 apart — see the ramp.
  • protanopia and deuteranopia and tritanopia shift it by ΔE00 13.9 and 13.2 and 10.5 — no red cone.

Text on this colour

White text

7.18:1 — passes AA

Black text

2.92:1 — fails AA

White text is the better of the two at7.18:1. That is enough for body text.

The same colour, with one cone missing

As you see it

#315b7d

protanopia

#57577d · ΔE00 13.9

deuteranopia

#51517d · ΔE00 13.2

tritanopia

#4a4aaf · ΔE00 10.5

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isMatisse at ΔE00 0.856: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.

  • MatisseΔE00 0.856 · #365c7d
  • Tidal WaveΔE00 1.269 · #355978
  • Venice BlueΔE00 1.469 · #2c5778
  • BlueyΔE00 1.599 · #375978
  • PelagicΔE00 1.627 · #355d83
  • Bahama BlueΔE00 1.693 · #25597f
  • Royal BreezeΔE00 1.836 · #275779
  • Chinese PorcelainΔE00 1.924 · #3a5f7d
  • Breonne BlueΔE00 2.113 · #2d567c
  • Queen of the NightΔE00 2.123 · #295776
  • Heavy BlueΔE00 2.188 · #2c5674
  • Water ChiΔE00 2.256 · #355873

12 of these have no page of their own: pages exist for the 4,961 colours the dataset marks as good names.