#183F7F
Closest named color: Twilight Blue (#0A437A). oklch(37.9% 0.117 259.9), rgb(24, 63, 127).
Aa
White text reads best on this color (10.21:1).
About this color
#183F7F is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.117 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.017 away. White text reads best on it, at 10.21:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.117) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.05:1 |
| White text | 10.21:1 |
Values
| HEX | #183F7F |
| RGB | rgb(24, 63, 127) |
| HSL | hsl(217, 68%, 30%) |
| OKLCH | oklch(37.9% 0.117 259.9) |
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 #183F7F | 10.21:1 | AAA | Lc -97.4 | Preferred for body text |
| Black text on #183F7F | 2.05:1 | Fails | Lc 10.6 | Not readable |
| #183F7F text on white | 10.21:1 | AAA | Lc 93.3 | Preferred for body text |
| #183F7F text on black | 2.05:1 | Fails | Lc -9.2 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E0EBFB
oklch(93.7% 0.025 257.6)
-
Step 200
200
#C7DAFA
oklch(88.4% 0.049 260.9)
-
Step 300
300
#A0C2FA
oklch(80.9% 0.088 260.2)
-
Step 400
400
#6BA0F7
oklch(70.7% 0.14 259.9)
-
Step 500
500
#4285F4
oklch(63% 0.18 260)
-
Step 600
600
#216CE3
oklch(55.7% 0.195 259.8)
-
Step 700
700
#1459C5
oklch(49.1% 0.181 259.9)
-
Step 800
800
#14499F
oklch(42.6% 0.15 260.1)
-
Step 900
900 (this color)
#183F7F
oklch(37.9% 0.117 259.9)
-
Step 950
950
#0F254A
oklch(27% 0.074 260.2)
#183F7F 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) | #1A4681 | 0.021 |
| Deuteranopia (no green cones) | #003D7E | 0.016 |
| Tritanopia (no blue cones) | #004E59 | 0.089 |
| Achromatopsia (no color) | #414141 | 0.117 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183F7F
#183F7F
oklch(37.9% 0.117 259.9)
- #583C00
#583C00
oklch(37.8% 0.079 79.1)
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 #183F7F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.017
- Cobalt #1E488F ΔE 0.037
- Marine Blue #01386A ΔE 0.045
- Light Navy #155084 ΔE 0.050
- Deep Sea Blue #015482 ΔE 0.061
- Dusk Blue #26538D ΔE 0.064
- Dark Slate Blue #483D8B ΔE 0.066
- Blueberry #464196 ΔE 0.071
Use #183F7F 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.