Andromeda Blue

#abcdee

A blue that is nearly neutral — the hue shows only against a true grey. It is very light — it works as a page background, not as text.

Hex

#abcdee

RGB

171, 205, 238

OKLCh

83.5% 0.059 247.8°

CIELAB (D50)

80.7, -6.1, -20.3

What is true of this colour, and of no other

  • 4 other named colours sit within ΔE00 2 of it.
  • It uses 68% of the chroma sRGB can show at this lightness and hue.
  • As text on white it measures APCA Lc 28.9; on black, Lc -74.0. 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 12.7 and 12.4 and 10.4 — no red cone.

Text on this colour

White text

1.65:1 — fails AA

Black text

12.70:1 — passes AA

Black text is the better of the two at12.70:1. That is enough for body text.

As text on white, it needs to change

#5a7a98 is the nearest colour of the same hue that passes AA on white, at 4.50:1. Only the lightness moved.

Try it against your own background

The same colour, with one cone missing

As you see it

#abcdee

protanopia

#cacaee · ΔE00 12.7

deuteranopia

#c4c4ef · ΔE00 12.4

tritanopia

#bdbdff · ΔE00 10.4

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isAlphabet Blue at ΔE00 0.294: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.

  • Alphabet BlueΔE00 0.294 · #abcdef
  • Blossom BlueΔE00 0.378 · #aaccee
  • Baby BuntingΔE00 0.982 · #abcaea
  • Island LightΔE00 1.029 · #a7c9eb
  • Baby Blue EyesΔE00 2.094 · #a1caf1
  • Blue VeilΔE00 2.106 · #aecbe5
  • BreezeΔE00 2.15 · #aec9ea
  • FeatherbedΔE00 2.184 · #afcbe5
  • Water WashΔE00 2.205 · #acc7e5
  • Tropical BlueΔE00 2.275 · #aec9eb
  • SailΔE00 2.339 · #a5ceec
  • TemplateΔE00 2.632 · #a6c9e3

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