#183C7B
Closest named color: Twilight Blue (#0A437A). oklch(36.9% 0.115 260.7), rgb(24, 60, 123).
Aa
White text reads best on this color (10.65:1).
About this color
#183C7B is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.115 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.021 away. White text reads best on it, at 10.65:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.115) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.97:1 |
| White text | 10.65:1 |
Values
| HEX | #183C7B |
| RGB | rgb(24, 60, 123) |
| HSL | hsl(218, 67%, 29%) |
| OKLCH | oklch(36.9% 0.115 260.7) |
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 #183C7B | 10.65:1 | AAA | Lc -98.3 | Preferred for body text |
| Black text on #183C7B | 1.97:1 | Fails | Lc 9.6 | Not readable |
| #183C7B text on white | 10.65:1 | AAA | Lc 94.3 | Preferred for body text |
| #183C7B text on black | 1.97:1 | Fails | Lc -8.3 | 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
#E1EBFB
oklch(93.7% 0.024 259.8)
-
Step 200
200
#C7DAFA
oklch(88.4% 0.049 260.9)
-
Step 300
300
#A1C2F9
oklch(81% 0.086 260.5)
-
Step 400
400
#6EA0F6
oklch(70.8% 0.138 260.7)
-
Step 500
500
#4685F2
oklch(63.1% 0.176 260.5)
-
Step 600
600
#286CE1
oklch(55.7% 0.191 260.6)
-
Step 700
700
#1B59C4
oklch(49.2% 0.179 260.7)
-
Step 800
800
#18499E
oklch(42.6% 0.148 260.7)
-
Step 900
900 (this color)
#183C7B
oklch(36.9% 0.115 260.7)
-
Step 950
950
#10254A
oklch(27% 0.074 260.8)
#183C7B 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) | #17437D | 0.020 |
| Deuteranopia (no green cones) | #003A7A | 0.017 |
| Tritanopia (no blue cones) | #004B55 | 0.090 |
| Achromatopsia (no color) | #3E3E3E | 0.115 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183C7B
#183C7B
oklch(36.9% 0.115 260.7)
- #543A00
#543A00
oklch(36.9% 0.076 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 #183C7B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.021
- Marine Blue #01386A ΔE 0.036
- Cobalt #1E488F ΔE 0.047
- Light Navy #155084 ΔE 0.059
- Prussian Blue #1D3557 ΔE 0.063
- Marine #042E60 ΔE 0.064
- Deep Sea Blue #015482 ΔE 0.070
- Dark Slate Blue #483D8B ΔE 0.070
Use #183C7B 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.