Deep Blue
#040273
A blue that is saturated. It is dark — it carries white text and needs care with black.
Hex
#040273
RGB
4, 2, 115
OKLCh
25.5% 0.171 265.6°
CIELAB (D50)
9.9, 37.0, -61.3
What is true of this colour, and of no other
- 5 other named colours sit within ΔE00 2 of it.
- It uses 98% of the chroma sRGB can show at this lightness and hue — close enough to the boundary that a wider display would show it slightly more vividly.
- As text on white it measures APCA Lc 101.9; on black, Lc 0.0. 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.
- All three dichromacies see it as very nearly the same colour you do: its hue is not the part carrying its identity.
Text on this colour
White text
16.65:1 — passes AA
Black text
1.26:1 — fails AA
White text is the better of the two at16.65:1. That is enough for body text.
The same colour, with one cone missing
As you see it
#040273
protanopia
#020273 · ΔE00 0.1
deuteranopia
#030373 · ΔE00 0.2
tritanopia
#030372 · ΔE00 0.2
The twelve nearest named colours
Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isScotch Blue at ΔE00 0.678: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.
- Scotch BlueΔE00 0.678 · #000077
- Dark RoyaltyΔE00 1.035 · #02066f
- Insomniac BlueΔE00 1.139 · #110077
- Quantum of LightΔE00 1.153 · #130173
- Navy BlueΔE00 1.815 · #000080
- Alone in the DarkΔE00 2.009 · #000066
- The Vast of NightΔE00 2.395 · #110066
- D. Darx BlueΔE00 2.483 · #030764
- Underground StreamΔE00 2.807 · #120a65
- Midnight in TokyoΔE00 2.879 · #000088
- PrunelleΔE00 2.886 · #220878
- Child of the NightΔE00 2.902 · #220077
7 of these have no page of their own: pages exist for the 4,961 colours the dataset marks as good names.