#12183A
Closest named color: Rich Black (#0D1B2A). oklch(22.5% 0.066 272.5), rgb(18, 24, 58).
Aa
White text reads best on this color (17.24:1).
About this color
#12183A is a very dark, muted blue. In OKLCH its lightness is 23%, its chroma 0.066 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Rich Black (#0D1B2A), ΔE 0.036 away. White text reads best on it, at 17.24:1.
| Hue family | Blues |
| Lightness | very dark (23%) |
| Chroma | muted (0.066) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.21:1 |
| White text | 17.24:1 |
Values
| HEX | #12183A |
| RGB | rgb(18, 24, 58) |
| HSL | hsl(231, 53%, 15%) |
| OKLCH | oklch(22.5% 0.066 272.5) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #12183A | 17.24:1 | AAA | Lc -106.3 | Preferred for body text |
| Black text on #12183A | 1.21:1 | Fails | Lc 0.0 | Not readable |
| #12183A text on white | 17.24:1 | AAA | Lc 104.0 | Preferred for body text |
| #12183A text on black | 1.21:1 | Fails | Lc 0.0 | Not readable |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 950.
-
Step 50
50
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E4E9F9
oklch(93.5% 0.022 272.1)
-
Step 200
200
#CFD8F7
oklch(88.5% 0.044 272.7)
-
Step 300
300
#AFBEF4
oklch(80.9% 0.078 272.5)
-
Step 400
400
#869BEE
oklch(70.8% 0.124 272.1)
-
Step 500
500
#6A7FE9
oklch(63.1% 0.16 272.6)
-
Step 600
600
#5366D7
oklch(55.6% 0.173 272.3)
-
Step 700
700
#4454BA
oklch(49.1% 0.161 272.4)
-
Step 800
800
#384597
oklch(42.7% 0.134 272.6)
-
Step 900
900
#303B78
oklch(37.7% 0.104 272.8)
-
Step 950
950 (this color)
#12183A
oklch(22.5% 0.066 272.5)
#12183A with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #061D3B | 0.020 |
| Deuteranopia (no green cones) | #011939 | 0.022 |
| Tritanopia (no blue cones) | #002026 | 0.057 |
| Achromatopsia (no color) | #1B1B1B | 0.066 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #12183A
#12183A
oklch(22.5% 0.066 272.5)
- #231B00
#231B00
oklch(22.5% 0.046 93.6)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #12183A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.036
- Navy Blue #001146 ΔE 0.042
- Oxford Blue #1B263B ΔE 0.050
- Dark #1B2431 ΔE 0.051
- Dark Indigo #1F0954 ΔE 0.061
- Night Blue #040348 ΔE 0.065
- Jet #212529 ΔE 0.068
- Midnight Purple #280137 ΔE 0.070
Use #12183A in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.