#183F60
Closest named color: Prussian Blue (#1D3557). oklch(35.7% 0.072 247.2), rgb(24, 63, 96).
Aa
White text reads best on this color (10.94:1).
About this color
#183F60 is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.072 and its hue 247°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.032 away. White text reads best on it, at 10.94:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.072) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.91:1 |
| White text | 10.94:1 |
Values
| HEX | #183F60 |
| RGB | rgb(24, 63, 96) |
| HSL | hsl(207, 60%, 24%) |
| OKLCH | oklch(35.7% 0.072 247.2) |
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 #183F60 | 10.94:1 | AAA | Lc -99.0 | Preferred for body text |
| Black text on #183F60 | 1.91:1 | Fails | Lc 8.8 | Not readable |
| #183F60 text on white | 10.94:1 | AAA | Lc 95.1 | Preferred for body text |
| #183F60 text on black | 1.91:1 | Fails | Lc -7.5 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E2EBF4
oklch(93.6% 0.016 248)
-
Step 200
200
#CADCEC
oklch(88.6% 0.029 244.9)
-
Step 300
300
#A5C5E2
oklch(81% 0.054 245.9)
-
Step 400
400
#74A6D4
oklch(70.8% 0.086 247.1)
-
Step 500
500
#4D8FC9
oklch(63.2% 0.111 247.1)
-
Step 600
600
#2D78B6
oklch(55.6% 0.121 247.3)
-
Step 700
700
#1F659C
oklch(49.2% 0.111 246.8)
-
Step 800
800
#1C527F
oklch(42.6% 0.094 247.5)
-
Step 900
900 (this color)
#183F60
oklch(35.7% 0.072 247.2)
-
Step 950
950
#12283C
oklch(26.9% 0.047 247.8)
#183F60 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) | #304061 | 0.028 |
| Deuteranopia (no green cones) | #26395F | 0.022 |
| Tritanopia (no blue cones) | #00474B | 0.053 |
| Achromatopsia (no color) | #3D3D3D | 0.072 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183F60
#183F60
oklch(35.7% 0.072 247.2)
- #553409
#553409
oklch(35.7% 0.072 67.5)
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 #183F60, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.032
- Dark Blue Grey #1F3B4D ΔE 0.033
- Dark Grey Blue #29465B ΔE 0.033
- Marine Blue #01386A ΔE 0.035
- Midnight Green #073B4C ΔE 0.039
- Charcoal #264653 ΔE 0.040
- Twilight Blue #0A437A ΔE 0.044
- Marine #042E60 ΔE 0.059
Use #183F60 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.