#183A4F
Closest named color: Dark Blue Grey (#1F3B4D). oklch(33.4% 0.054 238.5), rgb(24, 58, 79).
Aa
White text reads best on this color (11.95:1).
About this color
#183A4F is a dark, muted blue. In OKLCH its lightness is 33%, its chroma 0.054 and its hue 238°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Blue Grey (#1F3B4D), ΔE 0.009 away. White text reads best on it, at 11.95:1.
| Hue family | Blues |
| Lightness | dark (33%) |
| Chroma | muted (0.054) |
| Temperature | cool |
| Nearest name | Dark Blue Grey (#1F3B4D) |
| Black text | 1.75:1 |
| White text | 11.95:1 |
Values
| HEX | #183A4F |
| RGB | rgb(24, 58, 79) |
| HSL | hsl(203, 53%, 20%) |
| OKLCH | oklch(33.4% 0.054 238.5) |
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 #183A4F | 11.95:1 | AAA | Lc -100.8 | Preferred for body text |
| Black text on #183A4F | 1.75:1 | Fails | Lc 0.0 | Not readable |
| #183A4F text on white | 11.95:1 | AAA | Lc 97.2 | Preferred for body text |
| #183A4F text on black | 1.75:1 | 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
#E3EBF1
oklch(93.6% 0.012 239.9)
-
Step 200
200
#CCDCE7
oklch(88.6% 0.023 237.7)
-
Step 300
300
#A9C5D8
oklch(80.9% 0.041 237.7)
-
Step 400
400
#7BA7C5
oklch(70.8% 0.065 238.7)
-
Step 500
500
#5791B6
oklch(63.2% 0.083 238)
-
Step 600
600
#3A7AA2
oklch(55.5% 0.09 238.8)
-
Step 700
700
#2C678B
oklch(49.1% 0.084 238.6)
-
Step 800
800
#265471
oklch(42.7% 0.07 239)
-
Step 900
900 (this color)
#183A4F
oklch(33.4% 0.054 238.5)
-
Step 950
950
#162935
oklch(27.1% 0.033 237.5)
#183A4F 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) | #303A50 | 0.030 |
| Deuteranopia (no green cones) | #29344F | 0.026 |
| Tritanopia (no blue cones) | #003F41 | 0.038 |
| Achromatopsia (no color) | #373737 | 0.054 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183A4F
#183A4F
oklch(33.4% 0.054 238.5)
- #4B2F18
#4B2F18
oklch(33.4% 0.054 58.8)
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 #183A4F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Blue Grey #1F3B4D ΔE 0.009
- Midnight Green #073B4C ΔE 0.014
- Prussian Blue #1D3557 ΔE 0.025
- Gunmetal #293241 ΔE 0.034
- Onyx #343A40 ΔE 0.043
- Charcoal #264653 ΔE 0.044
- Space Cadet #2B2D42 ΔE 0.046
- Dark Grey Blue #29465B ΔE 0.048
Use #183A4F 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.