#183D5A
Closest named color: Dark Blue Grey (#1F3B4D). oklch(34.8% 0.066 245.1), rgb(24, 61, 90).
Aa
White text reads best on this color (11.32:1).
About this color
#183D5A is a dark, muted blue. In OKLCH its lightness is 35%, its chroma 0.066 and its hue 245°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Blue Grey (#1F3B4D), ΔE 0.023 away. White text reads best on it, at 11.32:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | muted (0.066) |
| Temperature | cool |
| Nearest name | Dark Blue Grey (#1F3B4D) |
| Black text | 1.85:1 |
| White text | 11.32:1 |
Values
| HEX | #183D5A |
| RGB | rgb(24, 61, 90) |
| HSL | hsl(206, 58%, 22%) |
| OKLCH | oklch(34.8% 0.066 245.1) |
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 #183D5A | 11.32:1 | AAA | Lc -99.7 | Preferred for body text |
| Black text on #183D5A | 1.85:1 | Fails | Lc 8.0 | Not readable |
| #183D5A text on white | 11.32:1 | AAA | Lc 95.9 | Preferred for body text |
| #183D5A text on black | 1.85:1 | Fails | Lc 0.0 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E2EBF3
oklch(93.6% 0.015 244.7)
-
Step 200
200
#CBDCEB
oklch(88.6% 0.028 244.7)
-
Step 300
300
#A7C5DF
oklch(81% 0.049 244.6)
-
Step 400
400
#76A6CF
oklch(70.7% 0.079 245)
-
Step 500
500
#518FC3
oklch(63% 0.102 245.7)
-
Step 600
600
#3279AF
oklch(55.6% 0.11 244.8)
-
Step 700
700
#246597
oklch(49% 0.103 245.6)
-
Step 800
800
#20537A
oklch(42.7% 0.084 244.9)
-
Step 900
900 (this color)
#183D5A
oklch(34.8% 0.066 245.1)
-
Step 950
950
#14283A
oklch(26.9% 0.043 247.2)
#183D5A 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) | #303E5B | 0.029 |
| Deuteranopia (no green cones) | #273759 | 0.023 |
| Tritanopia (no blue cones) | #004447 | 0.049 |
| Achromatopsia (no color) | #3A3A3A | 0.066 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183D5A
#183D5A
oklch(34.8% 0.066 245.1)
- #51320F
#51320F
oklch(34.8% 0.066 65.4)
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 #183D5A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Blue Grey #1F3B4D ΔE 0.023
- Prussian Blue #1D3557 ΔE 0.025
- Midnight Green #073B4C ΔE 0.029
- Dark Grey Blue #29465B ΔE 0.037
- Marine Blue #01386A ΔE 0.038
- Charcoal #264653 ΔE 0.039
- Gunmetal #293241 ΔE 0.050
- Onyx #343A40 ΔE 0.053
Use #183D5A 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.