#243F42
Closest named color: Onyx (#343A40). oklch(34.7% 0.033 204.8), rgb(36, 63, 66).
Aa
White text reads best on this color (11.26:1).
About this color
#243F42 is a dark, muted teal or cyan. In OKLCH its lightness is 35%, its chroma 0.033 and its hue 205°. Its hue sits on the cool side of the wheel. The nearest named color is Onyx (#343A40), ΔE 0.025 away. White text reads best on it, at 11.26:1.
| Hue family | Teals and cyans |
| Lightness | dark (35%) |
| Chroma | muted (0.033) |
| Temperature | cool |
| Nearest name | Onyx (#343A40) |
| Black text | 1.86:1 |
| White text | 11.26:1 |
Values
| HEX | #243F42 |
| RGB | rgb(36, 63, 66) |
| HSL | hsl(186, 29%, 20%) |
| OKLCH | oklch(34.7% 0.033 204.8) |
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 #243F42 | 11.26:1 | AAA | Lc -99.7 | Preferred for body text |
| Black text on #243F42 | 1.86:1 | Fails | Lc 8.0 | Not readable |
| #243F42 text on white | 11.26:1 | AAA | Lc 95.9 | Preferred for body text |
| #243F42 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
#F3F6F6
oklch(97.1% 0.003 197.1)
-
Step 100
100
#E5EBEC
oklch(93.6% 0.007 208.8)
-
Step 200
200
#CFDCDD
oklch(88.5% 0.014 202.4)
-
Step 300
300
#AFC6C8
oklch(81% 0.025 203)
-
Step 400
400
#84A8AC
oklch(70.6% 0.04 204.7)
-
Step 500
500
#649398
oklch(63.1% 0.051 204.3)
-
Step 600
600
#4A7D83
oklch(55.6% 0.056 205.3)
-
Step 700
700
#3B696F
oklch(49% 0.051 206.4)
-
Step 800
800
#31565A
oklch(42.7% 0.043 204.5)
-
Step 900
900 (this color)
#243F42
oklch(34.7% 0.033 204.8)
-
Step 950
950
#1A2A2B
oklch(27.1% 0.021 200.9)
#243F42 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) | #3B3D42 | 0.033 |
| Deuteranopia (no green cones) | #363942 | 0.031 |
| Tritanopia (no blue cones) | #174140 | 0.015 |
| Achromatopsia (no color) | #3B3B3B | 0.034 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243F42
#243F42
oklch(34.7% 0.033 204.8)
- #4A3331
#4A3331
oklch(34.7% 0.034 24.5)
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 #243F42, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Onyx #343A40 ΔE 0.025
- Dark Blue Grey #1F3B4D ΔE 0.028
- Charcoal #264653 ΔE 0.033
- Midnight Green #073B4C ΔE 0.035
- Charcoal Grey #3C4142 ΔE 0.035
- Gunmetal #293241 ΔE 0.044
- Dark Grey Blue #29465B ΔE 0.045
- Dark Teal #014D4E ΔE 0.046
Use #243F42 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.