#233F40
Closest named color: Onyx (#343A40). oklch(34.6% 0.034 198.6), rgb(35, 63, 64).
Aa
White text reads best on this color (11.31:1).
About this color
#233F40 is a dark, muted teal or cyan. In OKLCH its lightness is 35%, its chroma 0.034 and its hue 199°. Its hue sits on the cool side of the wheel. The nearest named color is Onyx (#343A40), ΔE 0.027 away. White text reads best on it, at 11.31:1.
| Hue family | Teals and cyans |
| Lightness | dark (35%) |
| Chroma | muted (0.034) |
| Temperature | cool |
| Nearest name | Onyx (#343A40) |
| Black text | 1.85:1 |
| White text | 11.31:1 |
Values
| HEX | #233F40 |
| RGB | rgb(35, 63, 64) |
| HSL | hsl(182, 29%, 19%) |
| OKLCH | oklch(34.6% 0.034 198.6) |
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 #233F40 | 11.31:1 | AAA | Lc -99.8 | Preferred for body text |
| Black text on #233F40 | 1.85:1 | Fails | Lc 7.9 | Not readable |
| #233F40 text on white | 11.31:1 | AAA | Lc 96.0 | Preferred for body text |
| #233F40 text on black | 1.85:1 | 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
#E4EBEC
oklch(93.5% 0.008 207.1)
-
Step 200
200
#CFDCDC
oklch(88.5% 0.014 196.9)
-
Step 300
300
#AEC6C7
oklch(80.9% 0.026 199.7)
-
Step 400
400
#83A9AA
oklch(70.7% 0.041 198.3)
-
Step 500
500
#639395
oklch(63% 0.052 199.2)
-
Step 600
600
#497E80
oklch(55.7% 0.057 198.8)
-
Step 700
700
#3A6A6C
oklch(49.1% 0.052 199.1)
-
Step 800
800
#305658
oklch(42.6% 0.043 200)
-
Step 900
900 (this color)
#233F40
oklch(34.6% 0.034 198.6)
-
Step 950
950
#1A2A2A
oklch(27.1% 0.021 196)
#233F40 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) | #3B3D40 | 0.034 |
| Deuteranopia (no green cones) | #363940 | 0.032 |
| Tritanopia (no blue cones) | #16413F | 0.014 |
| Achromatopsia (no color) | #3A3A3A | 0.034 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #233F40
#233F40
oklch(34.6% 0.034 198.6)
- #4A3233
#4A3233
oklch(34.6% 0.035 16.3)
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 #233F40, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Onyx #343A40 ΔE 0.027
- Dark Blue Grey #1F3B4D ΔE 0.031
- Charcoal #264653 ΔE 0.036
- Midnight Green #073B4C ΔE 0.037
- Charcoal Grey #3C4142 ΔE 0.037
- Gunmetal #293241 ΔE 0.045
- Dark Teal #014D4E ΔE 0.047
- Dark Grey Blue #29465B ΔE 0.049
Use #233F40 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.