Hadfield Blue
#1177ff
A blue that is saturated. It is mid — the hardest range to put text on, either colour struggles.
Hex
#1177ff
RGB
17, 119, 255
OKLCh
59.8% 0.220 258.7°
CIELAB (D50)
51.2, 14.4, -76.4
What is true of this colour, and of no other
- 7 other named colours sit within ΔE00 2 of it.
- 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 67.4; on black, Lc -34.2. 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 11.8 and 11.9 and 13.7 — no red cone.
Text on this colour
White text
4.11:1 — large text only
Black text
5.11:1 — passes AA
Black text is the better of the two at5.11:1. That is enough for body text.
As text on white, it needs to change
#0270f7 is the nearest colour of the same hue that passes AA on white, at 4.50:1. Only the lightness moved.
The same colour, with one cone missing
As you see it
#1177ff
protanopia
#7171ff · ΔE00 11.8
deuteranopia
#6666ff · ΔE00 11.9
tritanopia
#5757ff · ΔE00 13.7
The twelve nearest named colours
Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isBlue Sparkle at ΔE00 0.42: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.
- Blue SparkleΔE00 0.42 · #0077ff
- Clouded BlueΔE00 1.035 · #1f75fe
- Clear BlueΔE00 1.063 · #247afd
- Magic FountainΔE00 1.071 · #1f75ff
- Deep Sky BlueΔE00 1.075 · #0d75f8
- Blue DarknutΔE00 1.226 · #0078f8
- Hailey BlueΔE00 1.809 · #2c75ff
- Brandeis BlueΔE00 2.416 · #0070ff
- CeruleiteΔE00 2.637 · #337eff
- Lightish BlueΔE00 2.723 · #3d7afd
- AzureΔE00 3.029 · #007fff
- Brescian BlueΔE00 3.383 · #0080ff
10 of these have no page of their own: pages exist for the 4,961 colours the dataset marks as good names.