HueComb

Blue

#0000ff

A blue that is about as vivid as sRGB can show at this lightness. It is mid — the hardest range to put text on, either colour struggles.

Hex

#0000ff

RGB

0, 0, 255

OKLCh

45.2% 0.313 264.1°

CIELAB (D50)

29.6, 68.3, -112.0

What is true of this colour, and of no other

  • 10 other named colours sit within ΔE00 2 of it — this part of the space is crowded, and the names here are finer distinctions than most people make.
  • It sits exactly on the sRGB boundary: at this lightness and hue the gamut has nothing left, and a wider display would show a more colourful version of it.
  • As text on white it measures APCA Lc 85.8; on black, Lc -16.2. 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.
  • All three dichromacies see it as very nearly the same colour you do: its hue is not the part carrying its identity.

Text on this colour

White text

8.59:1 — passes AA

Black text

2.44:1 — fails AA

White text is the better of the two at8.59:1. That is enough for body text.

The same colour, with one cone missing

As you see it

#0000ff

protanopia

#0000ff · ΔE00 0.0

deuteranopia

#0000ff · ΔE00 0.0

tritanopia

#0000ff · ΔE00 0.0

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isGraphical 80’s Sky at ΔE00 0.356: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.

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