#183E98
Closest named color: Cobalt (#1E488F). oklch(39.7% 0.154 263.6), rgb(24, 62, 152).
Aa
White text reads best on this color (9.62:1).
About this color
#183E98 is a dark, vivid blue. In OKLCH its lightness is 40%, its chroma 0.154 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.033 away. White text reads best on it, at 9.62:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | vivid (0.154) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.18:1 |
| White text | 9.62:1 |
Values
| HEX | #183E98 |
| RGB | rgb(24, 62, 152) |
| HSL | hsl(222, 73%, 35%) |
| OKLCH | oklch(39.7% 0.154 263.6) |
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 #183E98 | 9.62:1 | AAA | Lc -96.0 | Preferred for body text |
| Black text on #183E98 | 2.18:1 | Fails | Lc 12.3 | Not readable |
| #183E98 text on white | 9.62:1 | AAA | Lc 91.7 | Preferred for body text |
| #183E98 text on black | 2.18:1 | Fails | Lc -10.7 | 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
#F1F6FF
oklch(97.2% 0.013 262.4)
-
Step 100
100
#DFEAFF
oklch(93.5% 0.031 263.5)
-
Step 200
200
#C6DAFF
oklch(88.5% 0.056 262.8)
-
Step 300
300
#A1C1FF
oklch(81% 0.095 263.3)
-
Step 400
400
#6E9DFF
oklch(70.6% 0.153 263.6)
-
Step 500
500
#4881FF
oklch(63.2% 0.197 263.5)
-
Step 600
600
#1F60FF
oklch(55.6% 0.244 263.5)
-
Step 700
700
#0E4AE4
oklch(49% 0.238 263.6)
-
Step 800
800
#0E3FB8
oklch(42.7% 0.197 263.5)
-
Step 900
900 (this color)
#183E98
oklch(39.7% 0.154 263.6)
-
Step 950
950
#0C2255
oklch(27% 0.097 263.6)
#183E98 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) | #004B9B | 0.034 |
| Deuteranopia (no green cones) | #003F96 | 0.013 |
| Tritanopia (no blue cones) | #005564 | 0.120 |
| Achromatopsia (no color) | #454545 | 0.154 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183E98
#183E98
oklch(39.7% 0.154 263.6)
- #5C4200
#5C4200
oklch(39.7% 0.082 83.1)
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 #183E98, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.033
- Sapphire #2138AB ΔE 0.034
- Twilight Blue #0A437A ΔE 0.054
- Blueberry #464196 ΔE 0.058
- Light Navy #155084 ΔE 0.063
- Dark Slate Blue #483D8B ΔE 0.064
- Dusk Blue #26538D ΔE 0.066
- Deep Sea Blue #015482 ΔE 0.075
Use #183E98 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.