#183D61
Closest named color: Prussian Blue (#1D3557). oklch(35.2% 0.076 250.3), rgb(24, 61, 97).
Aa
White text reads best on this color (11.17:1).
About this color
#183D61 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.076 and its hue 250°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.027 away. White text reads best on it, at 11.17:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.076) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.87:1 |
| White text | 11.17:1 |
Values
| HEX | #183D61 |
| RGB | rgb(24, 61, 97) |
| HSL | hsl(210, 60%, 24%) |
| OKLCH | oklch(35.2% 0.076 250.3) |
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 #183D61 | 11.17:1 | AAA | Lc -99.4 | Preferred for body text |
| Black text on #183D61 | 1.87:1 | Fails | Lc 8.3 | Not readable |
| #183D61 text on white | 11.17:1 | AAA | Lc 95.6 | Preferred for body text |
| #183D61 text on black | 1.87:1 | 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 900.
-
Step 50
50
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E2EBF5
oklch(93.6% 0.017 250.8)
-
Step 200
200
#CADBEE
oklch(88.5% 0.032 251.1)
-
Step 300
300
#A6C4E5
oklch(80.9% 0.057 251)
-
Step 400
400
#75A5D8
oklch(70.8% 0.091 250.7)
-
Step 500
500
#4F8ECD
oklch(63.2% 0.116 250.1)
-
Step 600
600
#3076BA
oklch(55.5% 0.127 250.7)
-
Step 700
700
#2263A0
oklch(49% 0.117 250.5)
-
Step 800
800
#1E5182
oklch(42.6% 0.098 250.5)
-
Step 900
900 (this color)
#183D61
oklch(35.2% 0.076 250.3)
-
Step 950
950
#13283D
oklch(27.1% 0.048 250)
#183D61 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) | #2D3F63 | 0.026 |
| Deuteranopia (no green cones) | #223860 | 0.017 |
| Tritanopia (no blue cones) | #00454A | 0.057 |
| Achromatopsia (no color) | #3B3B3B | 0.076 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183D61
#183D61
oklch(35.2% 0.076 250.3)
- #543301
#543301
oklch(35.3% 0.076 70)
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 #183D61, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.027
- Marine Blue #01386A ΔE 0.029
- Dark Blue Grey #1F3B4D ΔE 0.035
- Dark Grey Blue #29465B ΔE 0.039
- Midnight Green #073B4C ΔE 0.040
- Twilight Blue #0A437A ΔE 0.044
- Charcoal #264653 ΔE 0.046
- Marine #042E60 ΔE 0.052
Use #183D61 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.