Interstellar Blue
#001155
A blue that is muted. It is dark — it carries white text and needs care with black.
Hex
#001155
RGB
0, 17, 85
OKLCh
22.9% 0.123 263.6°
CIELAB (D50)
8.6, 19.3, -43.5
What is true of this colour, and of no other
- No other named colour in the set is within ΔE00 2 of it — it stands alone.
- 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 103.5; 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
17.34:1 — passes AA
Black text
1.21:1 — fails AA
White text is the better of the two at17.34:1. That is enough for body text.
The same colour, with one cone missing
As you see it
#001155
protanopia
#0f0f55 · ΔE00 2.2
deuteranopia
#0d0d55 · ΔE00 2.4
tritanopia
#09095c · ΔE00 3.3
The twelve nearest named colours
Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isShadowdancer at ΔE00 2.202: between 2 and 5 — clearly two colours when compared, easily mistaken from memory. What the numbers mean.
- ShadowdancerΔE00 2.202 · #111155
- Kantor BlueΔE00 2.766 · #001146
- Atlantic DepthsΔE00 2.798 · #001166
- StormΔE00 2.921 · #000b44
- Blue LatexΔE00 3.159 · #001144
- Space ColonisationΔE00 3.173 · #150f5b
- Dying Storm BlueΔE00 3.372 · #111166
- StratosΔE00 3.494 · #000741
- Night BlueΔE00 3.625 · #040348
- Endless GalaxyΔE00 3.751 · #000044
- Prussian NightsΔE00 3.845 · #0b085f
- Deep CoveΔE00 3.975 · #051040
8 of these have no page of their own: pages exist for the 4,961 colours the dataset marks as good names.