Overdue Blue
#4400ff
A blue that is about as vivid as sRGB can show at this lightness. It is mid — the hardest range to put text on, either colour struggles.
Hex
#4400ff
RGB
68, 0, 255
OKLCh
47.6% 0.300 274.9°
CIELAB (D50)
32.6, 70.0, -106.9
What is true of this colour, and of no other
- 5 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 84.1; on black, Lc -17.9. 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.
- tritanopia shifts it by ΔE00 5.1 — no blue cone.
Text on this colour
White text
7.81:1 — passes AA
Black text
2.69:1 — fails AA
White text is the better of the two at7.81:1. That is enough for body text.
The same colour, with one cone missing
As you see it
#4400ff
protanopia
#1313ff · ΔE00 3.1
deuteranopia
#2323ff · ΔE00 3.7
tritanopia
#2f2fea · ΔE00 5.1
The twelve nearest named colours
Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isElectric Ultramarine at ΔE00 0.448: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.
- Electric UltramarineΔE00 0.448 · #3f00ff
- Blustering BlueΔE00 0.978 · #4411ff
- Royal Hunter BlueΔE00 1.672 · #4411ee
- Radiant FeatherΔE00 1.771 · #5500ff
- Poseidon’s TerritoryΔE00 1.996 · #4400ee
- Han PurpleΔE00 2.025 · #5218fa
- Blue PencilΔE00 2.372 · #2200ff
- Tezcatlipōca BlueΔE00 2.397 · #5500ee
- Violet GlowΔE00 2.496 · #4422ee
- Delft BlueΔE00 2.508 · #3311ee
- Wèi Lán AzureΔE00 2.704 · #5a06ef
- Nimbus BlueΔE00 2.734 · #4422ff
11 of these have no page of their own: pages exist for the 4,961 colours the dataset marks as good names.