#18397F
Closest named color: Twilight Blue (#0A437A). oklch(36.5% 0.125 262.8), rgb(24, 57, 127).
Aa
White text reads best on this color (10.87:1).
About this color
#18397F is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.125 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.031 away. White text reads best on it, at 10.87:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.125) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.93:1 |
| White text | 10.87:1 |
Values
| HEX | #18397F |
| RGB | rgb(24, 57, 127) |
| HSL | hsl(221, 68%, 30%) |
| OKLCH | oklch(36.5% 0.125 262.8) |
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 #18397F | 10.87:1 | AAA | Lc -98.7 | Preferred for body text |
| Black text on #18397F | 1.93:1 | Fails | Lc 9.2 | Not readable |
| #18397F text on white | 10.87:1 | AAA | Lc 94.7 | Preferred for body text |
| #18397F text on black | 1.93:1 | Fails | Lc -7.9 | 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
#E0EAFD
oklch(93.5% 0.028 263.4)
-
Step 200
200
#C7DAFC
oklch(88.5% 0.051 262.1)
-
Step 300
300
#A1C1FE
oklch(81% 0.094 263)
-
Step 400
400
#6D9EFD
oklch(70.7% 0.149 262.5)
-
Step 500
500
#4782FB
oklch(63.1% 0.191 262.7)
-
Step 600
600
#2B67EB
oklch(55.6% 0.209 263)
-
Step 700
700
#1E55CC
oklch(49.1% 0.194 262.8)
-
Step 800
800
#1B46A5
oklch(42.6% 0.161 263)
-
Step 900
900 (this color)
#18397F
oklch(36.5% 0.125 262.8)
-
Step 950
950
#10244D
oklch(27% 0.08 262.7)
#18397F 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) | #034281 | 0.025 |
| Deuteranopia (no green cones) | #00387E | 0.016 |
| Tritanopia (no blue cones) | #004A56 | 0.097 |
| Achromatopsia (no color) | #3D3D3D | 0.125 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #18397F
#18397F
oklch(36.5% 0.125 262.8)
- #523A00
#523A00
oklch(36.6% 0.075 82.4)
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 #18397F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.031
- Marine Blue #01386A ΔE 0.040
- Cobalt #1E488F ΔE 0.049
- Marine #042E60 ΔE 0.065
- Light Navy #155084 ΔE 0.066
- Prussian Blue #1D3557 ΔE 0.069
- Dark Slate Blue #483D8B ΔE 0.070
- Sapphire #2138AB ΔE 0.074
Use #18397F 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.