#243B3F
Closest named color: Onyx (#343A40). oklch(33.5% 0.03 209.6), rgb(36, 59, 63).
Aa
White text reads best on this color (11.84:1).
About this color
#243B3F is a dark close to neutral grey. In OKLCH its lightness is 34%, its chroma 0.030. It has too little chroma to lean warm or cool. The nearest named color is Onyx (#343A40), ΔE 0.023 away. White text reads best on it, at 11.84:1.
| Hue family | Neutrals |
| Lightness | dark (34%) |
| Chroma | close to neutral grey (0.030) |
| Temperature | neutral |
| Nearest name | Onyx (#343A40) |
| Black text | 1.77:1 |
| White text | 11.84:1 |
Values
| HEX | #243B3F |
| RGB | rgb(36, 59, 63) |
| HSL | hsl(189, 27%, 19%) |
| OKLCH | oklch(33.5% 0.03 209.6) |
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 #243B3F | 11.84:1 | AAA | Lc -100.7 | Preferred for body text |
| Black text on #243B3F | 1.77:1 | Fails | Lc 0.0 | Not readable |
| #243B3F text on white | 11.84:1 | AAA | Lc 97.1 | Preferred for body text |
| #243B3F text on black | 1.77:1 | 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
#D0DBDD
oklch(88.4% 0.012 209.8)
-
Step 300
300
#B1C5C8
oklch(80.9% 0.022 207.6)
-
Step 400
400
#88A7AD
oklch(70.7% 0.035 210.7)
-
Step 500
500
#699199
oklch(63% 0.046 211.3)
-
Step 600
600
#507C83
oklch(55.7% 0.05 208.5)
-
Step 700
700
#40686F
oklch(49% 0.046 209.8)
-
Step 800
800
#36555A
oklch(42.7% 0.037 208.6)
-
Step 900
900 (this color)
#243B3F
oklch(33.5% 0.03 209.6)
-
Step 950
950
#1C292B
oklch(27% 0.018 207.9)
#243B3F 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) | #37393F | 0.028 |
| Deuteranopia (no green cones) | #33363F | 0.026 |
| Tritanopia (no blue cones) | #193D3C | 0.016 |
| Achromatopsia (no color) | #373737 | 0.030 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243B3F
#243B3F
oklch(33.5% 0.03 209.6)
- #45312E
#45312E
oklch(33.5% 0.03 28.4)
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 #243B3F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Onyx #343A40 ΔE 0.023
- Dark Blue Grey #1F3B4D ΔE 0.025
- Midnight Green #073B4C ΔE 0.032
- Gunmetal #293241 ΔE 0.032
- Charcoal Grey #3C4142 ΔE 0.043
- Charcoal #264653 ΔE 0.044
- Space Cadet #2B2D42 ΔE 0.050
- Prussian Blue #1D3557 ΔE 0.053
Use #243B3F 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.