#183E51
Closest named color: Dark Blue Grey (#1F3B4D). oklch(34.6% 0.054 233.2), rgb(24, 62, 81).
Aa
White text reads best on this color (11.37:1).
About this color
#183E51 is a dark, muted blue. In OKLCH its lightness is 35%, its chroma 0.054 and its hue 233°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Blue Grey (#1F3B4D), ΔE 0.011 away. White text reads best on it, at 11.37:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | muted (0.054) |
| Temperature | cool |
| Nearest name | Dark Blue Grey (#1F3B4D) |
| Black text | 1.84:1 |
| White text | 11.37:1 |
Values
| HEX | #183E51 |
| RGB | rgb(24, 62, 81) |
| HSL | hsl(200, 54%, 21%) |
| OKLCH | oklch(34.6% 0.054 233.2) |
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 #183E51 | 11.37:1 | AAA | Lc -99.8 | Preferred for body text |
| Black text on #183E51 | 1.84:1 | Fails | Lc 7.8 | Not readable |
| #183E51 text on white | 11.37:1 | AAA | Lc 96.0 | Preferred for body text |
| #183E51 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
#F2F6F8
oklch(97.1% 0.005 228.8)
-
Step 100
100
#E3EBF1
oklch(93.6% 0.012 239.9)
-
Step 200
200
#CBDCE6
oklch(88.5% 0.023 233.4)
-
Step 300
300
#A8C6D7
oklch(81% 0.04 232.8)
-
Step 400
400
#77A8C3
oklch(70.7% 0.065 233)
-
Step 500
500
#5292B4
oklch(63.1% 0.083 233.4)
-
Step 600
600
#337CA0
oklch(55.6% 0.091 233.2)
-
Step 700
700
#256889
oklch(49% 0.085 233.8)
-
Step 800
800
#21556F
oklch(42.7% 0.07 233.5)
-
Step 900
900 (this color)
#183E51
oklch(34.6% 0.054 233.2)
-
Step 950
950
#142935
oklch(26.9% 0.035 235.2)
#183E51 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) | #353D52 | 0.036 |
| Deuteranopia (no green cones) | #2D3751 | 0.031 |
| Tritanopia (no blue cones) | #004344 | 0.036 |
| Achromatopsia (no color) | #3A3A3A | 0.054 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183E51
#183E51
oklch(34.6% 0.054 233.2)
- #4F311D
#4F311D
oklch(34.5% 0.054 53.7)
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 #183E51, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Blue Grey #1F3B4D ΔE 0.011
- Midnight Green #073B4C ΔE 0.019
- Charcoal #264653 ΔE 0.032
- Prussian Blue #1D3557 ΔE 0.034
- Dark Grey Blue #29465B ΔE 0.036
- Onyx #343A40 ΔE 0.041
- Gunmetal #293241 ΔE 0.043
- Dark Teal #014D4E ΔE 0.053
Use #183E51 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.