Tip of the Iceberg

#bbe4ea

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

#bbe4ea

RGB

187, 228, 234

OKLCh

89.2% 0.043 207.3°

CIELAB (D50)

87.8, -12.8, -7.6

What is true of this colour, and of no other

29 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 41% of the chroma sRGB can show at this lightness and hue.
As text on white it measures APCA Lc 17.8; on black, Lc -85.8. 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 15.3 and 16.5 and 20.0 — no red cone.

Text on this colour

White text

1.36:1 — fails AA

Black text

15.40:1 — passes AA

Black text is the better of the two at15.40:1. That is enough for body text.

As text on white, it needs to change

#577d83 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

#bbe4ea

protanopia

#e0e0ea · ΔE00 15.3

deuteranopia

#d9d9eb · ΔE00 16.5

tritanopia

#d1d1ff · ΔE00 20.0

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isAquarelle Sky at ΔE00 0.538: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.

Aquarelle SkyΔE00 0.538 · #bce4eb
Icy WaterΔE00 0.821 · #bce2e8
Alaskan WindΔE00 0.836 · #bae3eb
ForeverΔE00 0.943 · #bbe1e6
Launderette BlueΔE00 1.125 · #c0e7eb
Early Forget-Me-NotΔE00 1.178 · #bae5ee
KyotoΔE00 1.204 · #bee3ea
First of JulyΔE00 1.246 · #bce6ef
Egg BlueΔE00 1.247 · #c1e7eb
Quench BlueΔE00 1.266 · #b4e0e7
Forgotten BlueΔE00 1.278 · #c0e5ec
La Paz SiestaΔE00 1.321 · #c1e5ea

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