#40D9DF
Closest named color: Aqua Blue (#02D8E9). oklch(81.1% 0.124 198.9), rgb(64, 217, 223).
Aa
Black text reads best on this color (12.20:1).
About this color
#40D9DF is a light, moderately saturated teal or cyan. In OKLCH its lightness is 81%, its chroma 0.124 and its hue 199°. Its hue sits on the cool side of the wheel. The nearest named color is Aqua Blue (#02D8E9), ΔE 0.020 away. Black text reads best on it, at 12.20:1.
| Hue family | Teals and cyans |
| Lightness | light (81%) |
| Chroma | moderately saturated (0.124) |
| Temperature | cool |
| Nearest name | Aqua Blue (#02D8E9) |
| Black text | 12.20:1 |
| White text | 1.72:1 |
Values
| HEX | #40D9DF |
| RGB | rgb(64, 217, 223) |
| HSL | hsl(182, 71%, 56%) |
| OKLCH | oklch(81.1% 0.124 198.9) |
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 #40D9DF | 1.72:1 | Fails | Lc -34.4 | Non-text elements, placeholder text |
| Black text on #40D9DF | 12.20:1 | AAA | Lc 73.2 | Content text, not long reading |
| #40D9DF text on white | 1.72:1 | Fails | Lc 30.6 | Non-text elements, placeholder text |
| #40D9DF text on black | 12.20:1 | AAA | Lc -72.2 | Content text, not long reading |
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 300.
-
Step 50
50
#E9F9FA
oklch(97.1% 0.017 201.4)
-
Step 100
100
#CFF2F3
oklch(93.6% 0.036 198.7)
-
Step 200
200
#A3E8EA
oklch(88.6% 0.069 198.3)
-
Step 300
300 (this color)
#40D9DF
oklch(81.1% 0.124 198.9)
-
Step 400
400
#00B7BD
oklch(70.8% 0.12 199)
-
Step 500
500
#009DA2
oklch(63.2% 0.107 198.8)
-
Step 600
600
#008488
oklch(55.7% 0.095 198.5)
-
Step 700
700
#006F72
oklch(49.2% 0.084 198.1)
-
Step 800
800
#005B5E
oklch(42.8% 0.073 198.7)
-
Step 900
900
#004C4E
oklch(37.8% 0.064 197.8)
-
Step 950
950
#002D2F
oklch(27% 0.046 199.4)
#40D9DF 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) | #C9CFE0 | 0.126 |
| Deuteranopia (no green cones) | #B2BEE0 | 0.118 |
| Tritanopia (no blue cones) | #00E1DA | 0.028 |
| Achromatopsia (no color) | #C5C5C5 | 0.124 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #40D9DF
#40D9DF
oklch(81.1% 0.124 198.9)
- #FFA5A6
#FFA5A6
oklch(81.1% 0.107 18.9)
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 #40D9DF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Aqua Blue #02D8E9 ΔE 0.020
- Medium Turquoise #48D1CC ΔE 0.029
- Turquoise #40E0D0 ΔE 0.034
- Dark Turquoise #00CED1 ΔE 0.040
- Vivid Sky Blue #4CC9F0 ΔE 0.057
- Seafoam Blue #78D1B6 ΔE 0.059
- Sky Blue #87CEEB ΔE 0.063
- Bright Sky Blue #02CCFE ΔE 0.068
Use #40D9DF 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.