Smalt
#003399
A blue that is saturated. It is dark — it carries white text and needs care with black.
Hex
#003399
RGB
0, 51, 153
OKLCh
37.1% 0.173 262.1°
CIELAB (D50)
24.7, 21.0, -60.7
What is true of this colour, and of no other
- 2 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 94.1; on black, Lc -8.5. 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 5.2 and 5.5 and 6.8 — no red cone.
Text on this colour
White text
10.86:1 — passes AA
Black text
1.93:1 — fails AA
White text is the better of the two at10.86:1. That is enough for body text.
The same colour, with one cone missing
As you see it
#003399
protanopia
#303099 · ΔE00 5.2
deuteranopia
#2a2a99 · ΔE00 5.5
tritanopia
#2323ad · ΔE00 6.8
The twelve nearest named colours
Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isDark Seashore Night at ΔE00 1.334: between 1 and 2 — a trained eye spots it when the two touch; nobody spots it across a room. What the numbers mean.
- Dark Seashore NightΔE00 1.334 · #113691
- US Air Force BlueΔE00 1.455 · #00308f
- Egyptian BlueΔE00 2 · #1034a6
- UA BlueΔE00 2.137 · #0033aa
- Philippine BlueΔE00 2.173 · #0038a7
- One Minute to MidnightΔE00 2.188 · #003388
- Blue HourΔE00 2.227 · #0034ab
- International Klein BlueΔE00 2.249 · #002fa6
- Royal AzureΔE00 2.259 · #0038a8
- International BlueΔE00 2.348 · #002fa7
- Amalfitan AzureΔE00 2.625 · #033b9a
- North Star BlueΔE00 2.694 · #223399
9 of these have no page of their own: pages exist for the 4,961 colours the dataset marks as good names.