Twinkle Night

#636ca8

A blue that is muted. It is mid — the hardest range to put text on, either colour struggles.

Hex

#636ca8

RGB

99, 108, 168

OKLCh

55.0% 0.094 276.4°

CIELAB (D50)

46.8, 8.5, -33.7

What is true of this colour, and of no other

  • 2 other named colours sit within ΔE00 2 of it.
  • It uses only 37% of the chroma available at this lightness and hue — there is a far more vivid version of this colour inside sRGB.
  • As text on white it measures APCA Lc 74.2; on black, Lc -27.5. 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

4.95:1 — passes AA

Black text

4.24:1 — large text only

White text is the better of the two at4.95:1. That is enough for body text.

The same colour, with one cone missing

As you see it

#636ca8

protanopia

#6b6ba8 · ΔE00 2.6

deuteranopia

#6969a8 · ΔE00 2.4

tritanopia

#6868b6 · ΔE00 2.7

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isMediaeval at ΔE00 1.637: between 1 and 2 — a trained eye spots it when the two touch; nobody spots it across a room. What the numbers mean.

  • MediaevalΔE00 1.637 · #696db0
  • Chalcedony VioletΔE00 1.667 · #6770ae
  • Chetwode BlueΔE00 2.077 · #666fb4
  • KimberliteΔE00 2.101 · #696fa5
  • Loch NessΔE00 2.148 · #5f6db0
  • BellflowerΔE00 2.363 · #5d66aa
  • Jacaranda JazzΔE00 2.608 · #6c70a9
  • Gladiola BlueΔE00 2.82 · #6370b6
  • Blue IrisΔE00 2.889 · #6264a6
  • Mountain Flower MauveΔE00 2.976 · #6c71a6
  • Dusted PeriΔE00 3.067 · #696ba0
  • DormitoryΔE00 3.105 · #5d71a9

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