#183A70
Closest named color: Marine Blue (#01386A). oklch(35.5% 0.102 259.4), rgb(24, 58, 112).
Aa
White text reads best on this color (11.18:1).
About this color
#183A70 is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.102 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.020 away. White text reads best on it, at 11.18:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.102) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.87:1 |
| White text | 11.18:1 |
Values
| HEX | #183A70 |
| RGB | rgb(24, 58, 112) |
| HSL | hsl(217, 65%, 27%) |
| OKLCH | oklch(35.5% 0.102 259.4) |
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 #183A70 | 11.18:1 | AAA | Lc -99.3 | Preferred for body text |
| Black text on #183A70 | 1.87:1 | Fails | Lc 8.4 | Not readable |
| #183A70 text on white | 11.18:1 | AAA | Lc 95.5 | Preferred for body text |
| #183A70 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF9
oklch(93.7% 0.022 256.7)
-
Step 200
200
#C9DAF6
oklch(88.4% 0.043 260.4)
-
Step 300
300
#A4C2F2
oklch(80.9% 0.076 259.7)
-
Step 400
400
#72A1EC
oklch(70.7% 0.122 259.4)
-
Step 500
500
#4C88E6
oklch(63.2% 0.155 259.1)
-
Step 600
600
#2F6FD4
oklch(55.6% 0.169 259.4)
-
Step 700
700
#225CB8
oklch(49.1% 0.158 259.6)
-
Step 800
800
#1E4C95
oklch(42.8% 0.13 259.5)
-
Step 900
900 (this color)
#183A70
oklch(35.5% 0.102 259.4)
-
Step 950
950
#122645
oklch(27% 0.064 258.9)
#183A70 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) | #1E3F72 | 0.017 |
| Deuteranopia (no green cones) | #09376F | 0.015 |
| Tritanopia (no blue cones) | #00474F | 0.080 |
| Achromatopsia (no color) | #3B3B3B | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183A70
#183A70
oklch(35.5% 0.102 259.4)
- #503700
#503700
oklch(35.6% 0.074 80.3)
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 #183A70, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.020
- Twilight Blue #0A437A ΔE 0.029
- Prussian Blue #1D3557 ΔE 0.044
- Marine #042E60 ΔE 0.049
- Dark Grey Blue #29465B ΔE 0.062
- Dark Blue Grey #1F3B4D ΔE 0.063
- Cobalt #1E488F ΔE 0.064
- Midnight Green #073B4C ΔE 0.067
Use #183A70 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.