Short answer
It depends on the source, which is the most useful thing to know about this pair. In CSS, midnight blue is slightly lighter than navy; in the crowd survey it is clearly darker. The one point every source agrees on is hue: midnight blue leans a few degrees further towards violet. Their regions share more than half of each other's colours, and their values sit only ΔE00 4.6–5.6 apart.
CSS navy (#000080) has OKLCH lightness 0.271; CSS midnight blue (#191970) has 0.288, so in CSS midnight blue is the lighter of the two, and it also carries less chroma (0.144 against 0.188). The crowd survey reverses the order: its navy has lightness 0.211 and its midnight blue 0.151, very close to black. Both agree on hue, with midnight blue a few degrees further round (273° against 264° in CSS; 268° against 260° in the survey). The lexicon therefore draws the two regions largely on top of each other — 50% of navy's grid colours are also midnight blue — and separates them only by midnight blue's reach towards violet and lower lightness.
Navy blue is named after the dark blue of British naval uniform, a colour fixed by a dye and a service, and it has kept a working, practical sense: uniforms, tailoring, school clothes. Midnight blue is a descriptive compound with no institution behind it. That difference in origin shows in how the names are used. Navy is expected to match other navy items and is treated almost as a neutral; midnight blue is chosen for depth and atmosphere, and whether it is lighter or darker than navy was never pinned down by anything except the maker's own swatch.
Both regions stop short of black only on chroma: black in the lexicon has chroma below 0.03, while navy and midnight blue start at 0.06. At these lightness levels the eye's sensitivity to colour falls away in dim light, so a very dark blue under a weak lamp looks black, and becomes blue again in daylight. The crowd's navy is ΔE00 19.4 from its black, far more than between the two blues — the difference exists, it is simply invisible in poor light. That is why navy-versus-black mismatches are found at the door, not in the shop.
When the names disagree about which is darker, the name is useless for matching. Compare physical samples in daylight or under high-CRI light, side by side, and look for the violet lean rather than depth: it is the one difference that survives across sources. For digital work, give OKLCH values; a navy and a midnight blue that differ by 0.05 in lightness and 8° in hue can be stated exactly and tested, where the words cannot. On screens, dark blues also vary with panel type, since LCD backlight lifts near-blacks and flattens the difference between very dark colours.
| Navy | Midnight blue | Shared by both | |
|---|---|---|---|
| Lightness (L) | 0.15–0.32 | 0.12–0.32 | 0.15–0.32 |
| Chroma (C) | 0.060–0.200 | 0.060–0.160 | 0.060–0.160 |
| Hue (h) | 250°–272° | 262°–285° | 262°–272° |
| Reference swatch | #000080 (L 0.27, C 0.188, h 264°) | #191970 (L 0.29, C 0.144, h 273°) | ΔE00 5.6 apart |
| sRGB grid colours inside | 38 | 35 | 19 (50% of navy, 54% of midnight blue) |
| How settled the word is | moderate | high | — |
| Source of the value | Navy | Midnight blue | ΔE00 between them |
|---|---|---|---|
| CSS Color 4 named colour | #000080 (L 0.27, C 0.188, h 264°) | #191970 (L 0.29, C 0.144, h 273°) | 5.6 |
| Colourwise catalogue profile | #000080 (L 0.27, C 0.188, h 264°) | #191970 (L 0.29, C 0.144, h 273°) | 5.6 |
| xkcd colour survey | #01153e (L 0.21, C 0.084, h 260°) | #020035 (L 0.15, C 0.101, h 268°) | 4.6 |
Each statement is labelled by kind — established fact, a standard’s requirement, observed market data, a convention, or Colourwise’s own interpretation or analysis — with the strength of the evidence behind it.
Colourwise analysisModerate evidence
In OKLCH, CSS navy has lightness 0.271 and CSS midnightblue 0.288, while the xkcd survey's navy has 0.211 and its midnight blue 0.151.
Based on: OKLCH computed by Colourwise from each source's published sRGB value.
Caveat: The survey centre reflects uncalibrated screens, where very dark colours vary most.
Source: CSS Color Module Level 4; Color survey results, and the rgb.txt list of the 954 most common colour names
FactModerate evidence
Navy blue was the colour of the British naval uniform, from which the name comes.
Caveat: The reference gives no date for the colour sense.
Source: Online Etymology Dictionary
StandardStrong evidence
CSS Color Level 4 defines navy as #000080 and midnightblue as #191970.
Source: CSS Color Module Level 4
Colourwise interpretationModerate evidence
The only difference between navy and midnight blue that holds across sources is midnight blue's slight lean towards violet; relative depth is not settled.
Based on: CSS and the crowd survey order the two names oppositely in lightness but place midnight blue at a higher hue angle in both.
Reviewed 29 September 2026. Colourwise summarises its sources in its own words and does not reproduce standards text or proprietary colour data. Spotted an error? Tell us.