Life at Sea

#afc9dc

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

#afc9dc

RGB

175, 201, 220

OKLCh

82.3% 0.039 239.7°

CIELAB (D50)

79.5, -6.0, -12.6

What is true of this colour, and of no other

19 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 39% 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 31.0; on black, Lc -71.8. 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 11.3 and 11.9 and 12.2 — no red cone.

Text on this colour

White text

1.72:1 — fails AA

Black text

12.21:1 — passes AA

Black text is the better of the two at12.21:1. That is enough for body text.

As text on white, it needs to change

#627a8b 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

#afc9dc

protanopia

#c6c6dc · ΔE00 11.3

deuteranopia

#c2c2dc · ΔE00 11.9

tritanopia

#bdbdff · ΔE00 12.2

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isWhiting Cottage at ΔE00 0.321: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.

Whiting CottageΔE00 0.321 · #aec9dc
Caspian TideΔE00 0.74 · #aec7db
Barking CreekΔE00 0.916 · #adc6da
Big SurΔE00 0.985 · #b3cadc
ChartedΔE00 1.081 · #b2cce1
Norwegian SkyΔE00 1.251 · #b4cdde
Dancing in the RainΔE00 1.299 · #abc5d6
Cache BlueΔE00 1.342 · #b5cee0
Blissful BlueΔE00 1.388 · #b2c8d8
Crystal WatersΔE00 1.448 · #b4cedf
OmphalodesΔE00 1.46 · #b5cedf
Wind BlueΔE00 1.528 · #b1c9df

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