#183D58
Closest named color: Dark Blue Grey (#1F3B4D). oklch(34.7% 0.063 243.2), rgb(24, 61, 88).
Aa
White text reads best on this color (11.36:1).
About this color
#183D58 is a dark, muted blue. In OKLCH its lightness is 35%, its chroma 0.063 and its hue 243°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Blue Grey (#1F3B4D), ΔE 0.019 away. White text reads best on it, at 11.36:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | muted (0.063) |
| Temperature | cool |
| Nearest name | Dark Blue Grey (#1F3B4D) |
| Black text | 1.84:1 |
| White text | 11.36:1 |
Values
| HEX | #183D58 |
| RGB | rgb(24, 61, 88) |
| HSL | hsl(205, 57%, 22%) |
| OKLCH | oklch(34.7% 0.063 243.2) |
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 #183D58 | 11.36:1 | AAA | Lc -99.8 | Preferred for body text |
| Black text on #183D58 | 1.84:1 | Fails | Lc 7.9 | Not readable |
| #183D58 text on white | 11.36:1 | AAA | Lc 96.0 | Preferred for body text |
| #183D58 text on black | 1.84:1 | 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
#F2F6F9
oklch(97.1% 0.006 239.8)
-
Step 100
100
#E2EBF3
oklch(93.6% 0.015 244.7)
-
Step 200
200
#CBDCEA
oklch(88.6% 0.027 242.8)
-
Step 300
300
#A7C5DD
oklch(80.9% 0.047 242.4)
-
Step 400
400
#77A6CD
oklch(70.6% 0.076 244.2)
-
Step 500
500
#5190C0
oklch(63.1% 0.098 243.2)
-
Step 600
600
#3379AC
oklch(55.5% 0.106 243.5)
-
Step 700
700
#256694
oklch(49.1% 0.098 243.4)
-
Step 800
800
#205378
oklch(42.6% 0.082 243.5)
-
Step 900
900 (this color)
#183D58
oklch(34.7% 0.063 243.2)
-
Step 950
950
#142939
oklch(27.2% 0.04 243)
#183D58 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) | #313E59 | 0.030 |
| Deuteranopia (no green cones) | #283758 | 0.024 |
| Tritanopia (no blue cones) | #004446 | 0.047 |
| Achromatopsia (no color) | #3A3A3A | 0.063 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183D58
#183D58
oklch(34.7% 0.063 243.2)
- #513212
#513212
oklch(34.8% 0.064 63.6)
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 #183D58, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Blue Grey #1F3B4D ΔE 0.019
- Prussian Blue #1D3557 ΔE 0.025
- Midnight Green #073B4C ΔE 0.026
- Dark Grey Blue #29465B ΔE 0.037
- Charcoal #264653 ΔE 0.038
- Marine Blue #01386A ΔE 0.041
- Gunmetal #293241 ΔE 0.048
- Onyx #343A40 ΔE 0.050
Use #183D58 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.