Opal

#aee0e4

A cyan 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

#aee0e4

RGB

174, 224, 228

OKLCh

87.3% 0.052 202.3°

CIELAB (D50)

85.8, -16.0, -7.5

What is true of this colour, and of no other

11 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 uses only 35% 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 21.0; on black, Lc -82.3. 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 17.3 and 18.8 and 21.9 — no red cone.

Text on this colour

White text

1.44:1 — fails AA

Black text

14.58:1 — passes AA

Black text is the better of the two at14.58:1. That is enough for body text.

As text on white, it needs to change

#4f7e82 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

#aee0e4

protanopia

#dbdbe4 · ΔE00 17.3

deuteranopia

#d3d3e5 · ΔE00 18.8

tritanopia

#c9c9ff · ΔE00 21.9

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isBlue Bauble at ΔE00 0.637: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.

Blue BaubleΔE00 0.637 · #abdee3
VandermintΔE00 0.905 · #abdee4
Powder BlueΔE00 1 · #b0e0e6
Geyser PoolΔE00 1.219 · #a9dce2
Sky CloudΔE00 1.314 · #addee5
Across the BayΔE00 1.715 · #b3e1e8
Winter EscapeΔE00 1.763 · #b4e5ec
Polar BlueΔE00 1.847 · #b3e0e7
Seascape GreenΔE00 1.89 · #b5e4e4
Soaring SkyΔE00 1.917 · #b9e5e8
Beachside DriveΔE00 1.958 · #acdbdb
CrystalΔE00 2.004 · #a7d8de

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