Ahoy! Blue

#0082a1

A cyan that is muted. It is mid — the hardest range to put text on, either colour struggles.

Hex

#0082a1

RGB

0, 130, 161

OKLCh

56.3% 0.104 222.3°

CIELAB (D50)

49.7, -22.3, -25.6

What is true of this colour, and of no other

12 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 sits exactly on the sRGB boundary: at this lightness and hue the gamut has nothing left, and a wider display would show a more colourful version of it.
As text on white it measures APCA Lc 70.4; on black, Lc -31.3. 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 23.1 and 22.6 and 23.2 — no red cone.

Text on this colour

White text

4.46:1 — large text only

Black text

4.71:1 — passes AA

Black text is the better of the two at4.71:1. That is enough for body text.

As text on white, it needs to change

#0081a0 is the nearest colour of the same hue that passes AA on white, at 4.50:1. Only the lightness moved, and some saturation was given up to stay inside sRGB.

Try it against your own background

The same colour, with one cone missing

As you see it

#0082a1

protanopia

#7b7ba1 · ΔE00 23.1

deuteranopia

#6f6fa2 · ΔE00 22.6

tritanopia

#5e5eff · ΔE00 23.2

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isBest of Both Worlds at ΔE00 0.736: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.

Best of Both WorldsΔE00 0.736 · #01809f
Decore SplashΔE00 0.993 · #00829e
Deep UniverseΔE00 1.105 · #017f9e
Amazing SkyΔE00 1.135 · #017f9d
Tibetan TurquoiseΔE00 1.189 · #0084a6
Summer BlueΔE00 1.43 · #1880a1
Azores BlueΔE00 1.435 · #0085a7
Blue ArcΔE00 1.51 · #0085a1
Turkish TileΔE00 1.639 · #007e9f
Kingfisher SheenΔE00 1.736 · #007fa2
Caribbean SeaΔE00 1.85 · #0087a7
Hacienda BlueΔE00 1.919 · #0087a8

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