Jack-O

#fb9902

An orange that is saturated. It is light — black text sits on it comfortably, white text does not.

Hex

#fb9902

RGB

251, 153, 2

OKLCh

76.7% 0.171 65.7°

CIELAB (D50)

72.4, 31.8, 76.7

What is true of this colour, and of no other

16 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 42.3; on black, Lc -59.9. 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 25.6 and 25.9 and 27.2 — no red cone.

Text on this colour

White text

2.17:1 — fails AA

Black text

9.66:1 — passes AA

Black text is the better of the two at9.66:1. That is enough for body text.

As text on white, it needs to change

#ab6700 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

#fb9902

protanopia

#a8a80b · ΔE00 25.6

deuteranopia

#bdbd00 · ΔE00 25.9

tritanopia

#d1d100 · ΔE00 27.2

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isAromango at ΔE00 0.804: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.

AromangoΔE00 0.804 · #f9970c
Vitamin CΔE00 0.821 · #ff9900
DodgeRoll GoldΔE00 0.879 · #f79a12
Clementine EarringΔE00 1.063 · #ff9d0a
ZambiaΔE00 1.156 · #ff990e
Orange FruitΔE00 1.219 · #fe9e13
Hephaestus GoldΔE00 1.272 · #ff9911
Laughing OrangeΔE00 1.326 · #f49807
Radiant YellowΔE00 1.406 · #fc9e21
Kin GoldΔE00 1.641 · #f39800
Sunset BoulevardΔE00 1.734 · #ff9607
Mandarin PeelΔE00 1.736 · #ff9f00

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