Subtle Breeze

#b5d2d8

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

#b5d2d8

RGB

181, 210, 216

OKLCh

84.4% 0.032 211.6°

CIELAB (D50)

82.2, -9.1, -6.4

What is true of this colour, and of no other

18 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 23% 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 26.9; on black, Lc -76.1. 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 12.1 and 13.1 and 18.8 — no red cone.

Text on this colour

White text

1.59:1 — fails AA

Black text

13.17:1 — passes AA

Black text is the better of the two at13.17:1. That is enough for body text.

As text on white, it needs to change

#607b81 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

#b5d2d8

protanopia

#cfcfd8 · ΔE00 12.1

deuteranopia

#cacad9 · ΔE00 13.1

tritanopia

#c4c4ff · ΔE00 18.8

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isHatchling Blue at ΔE00 0.907: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.

Hatchling BlueΔE00 0.907 · #b2d1d6
Clinical Soft BlueΔE00 1.167 · #b2cfd3
Light Sky ChaseΔE00 1.263 · #bad7dc
DewpointΔE00 1.284 · #b2ced2
Everglade MistΔE00 1.368 · #b7d7de
HeavenΔE00 1.399 · #b4ced5
Rain CheckΔE00 1.408 · #b6d5de
Starlight BlueΔE00 1.471 · #b5ced4
Midsummer’s DreamΔE00 1.477 · #b4d0d9
Pallid BlueΔE00 1.554 · #b3cdd4
ElevationΔE00 1.634 · #b5ced5
Blue GlowΔE00 1.64 · #b2d4dd

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