#183DA0
Closest named color: Sapphire (#2138AB). oklch(40.3% 0.166 264.3), rgb(24, 61, 160).
Aa
White text reads best on this color (9.48:1).
About this color
#183DA0 is a dark, vivid blue. In OKLCH its lightness is 40%, its chroma 0.166 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.022 away. White text reads best on it, at 9.48:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | vivid (0.166) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.21:1 |
| White text | 9.48:1 |
Values
| HEX | #183DA0 |
| RGB | rgb(24, 61, 160) |
| HSL | hsl(224, 74%, 36%) |
| OKLCH | oklch(40.3% 0.166 264.3) |
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 #183DA0 | 9.48:1 | AAA | Lc -95.6 | Preferred for body text |
| Black text on #183DA0 | 2.21:1 | Fails | Lc 12.7 | Not readable |
| #183DA0 text on white | 9.48:1 | AAA | Lc 91.2 | Preferred for body text |
| #183DA0 text on black | 2.21:1 | Fails | Lc -11.1 | 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 800.
-
Step 50
50
#F1F6FF
oklch(97.2% 0.013 262.4)
-
Step 100
100
#E1EAFD
oklch(93.6% 0.028 265.4)
-
Step 200
200
#C7D9FE
oklch(88.4% 0.055 264.7)
-
Step 300
300
#A2C0FF
oklch(80.9% 0.096 264.7)
-
Step 400
400
#709DFF
oklch(70.7% 0.152 264.2)
-
Step 500
500
#4B80FF
oklch(63.1% 0.197 264.4)
-
Step 600
600
#3065EF
oklch(55.6% 0.216 264.4)
-
Step 700
700
#2352D0
oklch(49% 0.201 264.4)
-
Step 800
800 (this color)
#183DA0
oklch(40.3% 0.166 264.3)
-
Step 900
900
#1D3B85
oklch(37.7% 0.13 264.4)
-
Step 950
950
#11234E
oklch(26.9% 0.083 264.4)
#183DA0 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) | #004CA3 | 0.037 |
| Deuteranopia (no green cones) | #00409E | 0.013 |
| Tritanopia (no blue cones) | #005768 | 0.129 |
| Achromatopsia (no color) | #464646 | 0.166 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183DA0
#183DA0
oklch(40.3% 0.166 264.3)
- #5D4400
#5D4400
oklch(40.3% 0.083 84.7)
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 #183DA0, closest first.
No curated palette has a color within ΔE 0.04 of #183DA0.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.022
- Cobalt #1E488F ΔE 0.042
- Blueberry #464196 ΔE 0.061
- Blue Blue #2242C7 ΔE 0.066
- Twilight Blue #0A437A ΔE 0.067
- Dark Slate Blue #483D8B ΔE 0.069
- Indigo Blue #3A18B1 ΔE 0.072
- Dusk Blue #26538D ΔE 0.073
Use #183DA0 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.