#12437F
Closest named color: Twilight Blue (#0A437A). oklch(38.6% 0.114 256), rgb(18, 67, 127).
Aa
White text reads best on this color (9.83:1).
About this color
#12437F is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.114 and its hue 256°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.010 away. White text reads best on it, at 9.83:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.114) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.13:1 |
| White text | 9.83:1 |
Values
| HEX | #12437F |
| RGB | rgb(18, 67, 127) |
| HSL | hsl(213, 75%, 28%) |
| OKLCH | oklch(38.6% 0.114 256) |
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 #12437F | 9.83:1 | AAA | Lc -96.6 | Preferred for body text |
| Black text on #12437F | 2.13:1 | Fails | Lc 11.6 | Not readable |
| #12437F text on white | 9.83:1 | AAA | Lc 92.4 | Preferred for body text |
| #12437F text on black | 2.13:1 | Fails | Lc -10.1 | 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 900.
-
Step 50
50
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#DFEBFB
oklch(93.6% 0.025 255.6)
-
Step 200
200
#C5DBF9
oklch(88.5% 0.048 256.2)
-
Step 300
300
#9DC3F8
oklch(80.9% 0.086 256.8)
-
Step 400
400
#65A2F4
oklch(70.6% 0.137 256.2)
-
Step 500
500
#3688F0
oklch(63% 0.175 256.1)
-
Step 600
600
#016FDE
oklch(55.5% 0.189 256)
-
Step 700
700
#005DBD
oklch(49.1% 0.169 256.1)
-
Step 800
800
#004C9C
oklch(42.7% 0.146 256)
-
Step 900
900 (this color)
#12437F
oklch(38.6% 0.114 256)
-
Step 950
950
#0B2649
oklch(27% 0.073 256.3)
#12437F 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) | #234981 | 0.024 |
| Deuteranopia (no green cones) | #073F7E | 0.014 |
| Tritanopia (no blue cones) | #00515A | 0.086 |
| Achromatopsia (no color) | #434343 | 0.114 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #12437F
#12437F
oklch(38.6% 0.114 256)
- #5C3D00
#5C3D00
oklch(38.6% 0.081 76.6)
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 #12437F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.010
- Cobalt #1E488F ΔE 0.032
- Light Navy #155084 ΔE 0.039
- Marine Blue #01386A ΔE 0.049
- Deep Sea Blue #015482 ΔE 0.050
- Dusk Blue #26538D ΔE 0.055
- Dark Grey Blue #29465B ΔE 0.067
- Dark Slate Blue #483D8B ΔE 0.069
Use #12437F 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.