#183F51
Closest named color: Dark Blue Grey (#1F3B4D). oklch(34.8% 0.054 231.1), rgb(24, 63, 81).
Aa
White text reads best on this color (11.23:1).
About this color
#183F51 is a dark, muted blue. In OKLCH its lightness is 35%, its chroma 0.054 and its hue 231°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Blue Grey (#1F3B4D), ΔE 0.014 away. White text reads best on it, at 11.23:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | muted (0.054) |
| Temperature | cool |
| Nearest name | Dark Blue Grey (#1F3B4D) |
| Black text | 1.86:1 |
| White text | 11.23:1 |
Values
| HEX | #183F51 |
| RGB | rgb(24, 63, 81) |
| HSL | hsl(199, 54%, 21%) |
| OKLCH | oklch(34.8% 0.054 231.1) |
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 #183F51 | 11.23:1 | AAA | Lc -99.6 | Preferred for body text |
| Black text on #183F51 | 1.86:1 | Fails | Lc 8.1 | Not readable |
| #183F51 text on white | 11.23:1 | AAA | Lc 95.8 | Preferred for body text |
| #183F51 text on black | 1.86:1 | 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
#F2F6F8
oklch(97.1% 0.005 228.8)
-
Step 100
100
#E2EBF0
oklch(93.5% 0.012 231.7)
-
Step 200
200
#CBDCE5
oklch(88.4% 0.022 230.6)
-
Step 300
300
#A7C6D6
oklch(80.9% 0.04 230.3)
-
Step 400
400
#77A8C2
oklch(70.6% 0.065 232)
-
Step 500
500
#5193B2
oklch(63.2% 0.082 230.3)
-
Step 600
600
#327C9E
oklch(55.5% 0.089 231.5)
-
Step 700
700
#236987
oklch(49.1% 0.083 230.5)
-
Step 800
800
#20566E
oklch(42.8% 0.069 230.6)
-
Step 900
900 (this color)
#183F51
oklch(34.8% 0.054 231.1)
-
Step 950
950
#142934
oklch(26.9% 0.034 232.8)
#183F51 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) | #363E52 | 0.037 |
| Deuteranopia (no green cones) | #2E3851 | 0.032 |
| Tritanopia (no blue cones) | #004445 | 0.034 |
| Achromatopsia (no color) | #3B3B3B | 0.054 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183F51
#183F51
oklch(34.8% 0.054 231.1)
- #50321F
#50321F
oklch(34.9% 0.053 52.5)
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 #183F51, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Blue Grey #1F3B4D ΔE 0.014
- Midnight Green #073B4C ΔE 0.021
- Charcoal #264653 ΔE 0.029
- Dark Grey Blue #29465B ΔE 0.034
- Prussian Blue #1D3557 ΔE 0.037
- Onyx #343A40 ΔE 0.041
- Gunmetal #293241 ΔE 0.046
- Dark Teal #014D4E ΔE 0.049
Use #183F51 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.