#243C39
Closest named color: Onyx (#343A40). oklch(33.5% 0.03 185.9), rgb(36, 60, 57).
Aa
White text reads best on this color (11.79:1).
About this color
#243C39 is a dark, muted teal or cyan. In OKLCH its lightness is 34%, its chroma 0.030 and its hue 186°. Its hue sits on the cool side of the wheel. The nearest named color is Onyx (#343A40), ΔE 0.029 away. White text reads best on it, at 11.79:1.
| Hue family | Teals and cyans |
| Lightness | dark (34%) |
| Chroma | muted (0.030) |
| Temperature | cool |
| Nearest name | Onyx (#343A40) |
| Black text | 1.78:1 |
| White text | 11.79:1 |
Values
| HEX | #243C39 |
| RGB | rgb(36, 60, 57) |
| HSL | hsl(173, 25%, 19%) |
| OKLCH | oklch(33.5% 0.03 185.9) |
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 #243C39 | 11.79:1 | AAA | Lc -100.6 | Preferred for body text |
| Black text on #243C39 | 1.78:1 | Fails | Lc 0.0 | Not readable |
| #243C39 text on white | 11.79:1 | AAA | Lc 97.0 | Preferred for body text |
| #243C39 text on black | 1.78:1 | 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
#E5EBEA
oklch(93.5% 0.007 185.3)
-
Step 200
200
#D0DCDA
oklch(88.5% 0.013 185.1)
-
Step 300
300
#B1C6C3
oklch(81% 0.023 186.4)
-
Step 400
400
#88A8A4
oklch(70.6% 0.036 187.1)
-
Step 500
500
#69938E
oklch(63.1% 0.047 186.9)
-
Step 600
600
#507D78
oklch(55.6% 0.05 187)
-
Step 700
700
#406A65
oklch(49.2% 0.048 186.2)
-
Step 800
800
#355652
oklch(42.6% 0.039 186.2)
-
Step 900
900 (this color)
#243C39
oklch(33.5% 0.03 185.9)
-
Step 950
950
#1C2A28
oklch(27.2% 0.019 185.2)
#243C39 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) | #3A3939 | 0.033 |
| Deuteranopia (no green cones) | #353639 | 0.031 |
| Tritanopia (no blue cones) | #1C3D3B | 0.009 |
| Achromatopsia (no color) | #383838 | 0.031 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243C39
#243C39
oklch(33.5% 0.03 185.9)
- #453034
#453034
oklch(33.5% 0.031 6.3)
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 #243C39, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Onyx #343A40 ΔE 0.029
- Dark Blue Grey #1F3B4D ΔE 0.037
- Midnight Green #073B4C ΔE 0.041
- Gunmetal #293241 ΔE 0.042
- Charcoal Grey #3C4142 ΔE 0.043
- Charcoal #264653 ΔE 0.049
- Pakistan Green #283618 ΔE 0.050
- Evergreen #05472A ΔE 0.057
Use #243C39 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.