#243D40
Closest named color: Onyx (#343A40). oklch(34.1% 0.031 205.4), rgb(36, 61, 64).
Aa
White text reads best on this color (11.56:1).
About this color
#243D40 is a dark, muted teal or cyan. In OKLCH its lightness is 34%, its chroma 0.031 and its hue 205°. Its hue sits on the cool side of the wheel. The nearest named color is Onyx (#343A40), ΔE 0.024 away. White text reads best on it, at 11.56:1.
| Hue family | Teals and cyans |
| Lightness | dark (34%) |
| Chroma | muted (0.031) |
| Temperature | cool |
| Nearest name | Onyx (#343A40) |
| Black text | 1.81:1 |
| White text | 11.56:1 |
Values
| HEX | #243D40 |
| RGB | rgb(36, 61, 64) |
| HSL | hsl(186, 28%, 20%) |
| OKLCH | oklch(34.1% 0.031 205.4) |
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 #243D40 | 11.56:1 | AAA | Lc -100.2 | Preferred for body text |
| Black text on #243D40 | 1.81:1 | Fails | Lc 7.3 | Not readable |
| #243D40 text on white | 11.56:1 | AAA | Lc 96.6 | Preferred for body text |
| #243D40 text on black | 1.81:1 | 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
#F3F6F6
oklch(97.1% 0.003 197.1)
-
Step 100
100
#E5EBEC
oklch(93.6% 0.007 208.8)
-
Step 200
200
#D0DCDD
oklch(88.6% 0.013 202.9)
-
Step 300
300
#B0C5C8
oklch(80.8% 0.023 207.1)
-
Step 400
400
#86A8AC
oklch(70.8% 0.038 205.2)
-
Step 500
500
#679297
oklch(63% 0.047 205.1)
-
Step 600
600
#4D7C82
oklch(55.5% 0.052 206.1)
-
Step 700
700
#3E696E
oklch(49.2% 0.048 205.2)
-
Step 800
800
#33555A
oklch(42.6% 0.04 207.6)
-
Step 900
900 (this color)
#243D40
oklch(34.1% 0.031 205.4)
-
Step 950
950
#1B292B
oklch(26.9% 0.019 207.1)
#243D40 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) | #393B40 | 0.030 |
| Deuteranopia (no green cones) | #343740 | 0.029 |
| Tritanopia (no blue cones) | #183F3E | 0.015 |
| Achromatopsia (no color) | #393939 | 0.031 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243D40
#243D40
oklch(34.1% 0.031 205.4)
- #473230
#473230
oklch(34.1% 0.031 25)
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 #243D40, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Onyx #343A40 ΔE 0.024
- Dark Blue Grey #1F3B4D ΔE 0.027
- Midnight Green #073B4C ΔE 0.034
- Gunmetal #293241 ΔE 0.038
- Charcoal Grey #3C4142 ΔE 0.039
- Charcoal #264653 ΔE 0.039
- Dark Grey Blue #29465B ΔE 0.050
- Dark Teal #014D4E ΔE 0.053
Use #243D40 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.