#40D3DF
Closest named color: Aqua Blue (#02D8E9). oklch(79.6% 0.121 203.1), rgb(64, 211, 223).
Aa
Black text reads best on this color (11.60:1).
About this color
#40D3DF is a light, moderately saturated teal or cyan. In OKLCH its lightness is 80%, its chroma 0.121 and its hue 203°. Its hue sits on the cool side of the wheel. The nearest named color is Aqua Blue (#02D8E9), ΔE 0.019 away. Black text reads best on it, at 11.60:1.
| Hue family | Teals and cyans |
| Lightness | light (80%) |
| Chroma | moderately saturated (0.121) |
| Temperature | cool |
| Nearest name | Aqua Blue (#02D8E9) |
| Black text | 11.60:1 |
| White text | 1.81:1 |
Values
| HEX | #40D3DF |
| RGB | rgb(64, 211, 223) |
| HSL | hsl(185, 71%, 56%) |
| OKLCH | oklch(79.6% 0.121 203.1) |
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 #40D3DF | 1.81:1 | Fails | Lc -37.3 | Non-text elements, placeholder text |
| Black text on #40D3DF | 11.60:1 | AAA | Lc 70.6 | Content text, not long reading |
| #40D3DF text on white | 1.81:1 | Fails | Lc 33.3 | Non-text elements, placeholder text |
| #40D3DF text on black | 11.60:1 | AAA | Lc -69.3 | 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
#EAF9FA
oklch(97.1% 0.016 201.7)
-
Step 100
100
#D0F1F4
oklch(93.5% 0.035 203.3)
-
Step 200
200
#A4E7ED
oklch(88.5% 0.067 203)
-
Step 300
300 (this color)
#40D3DF
oklch(79.6% 0.121 203.1)
-
Step 400
400
#00B6C2
oklch(70.7% 0.12 203.2)
-
Step 500
500
#009CA6
oklch(63.1% 0.107 202.8)
-
Step 600
600
#00838C
oklch(55.6% 0.095 203.3)
-
Step 700
700
#006E76
oklch(49.1% 0.084 203.6)
-
Step 800
800
#005A61
oklch(42.6% 0.073 204)
-
Step 900
900
#004B51
oklch(37.6% 0.064 204)
-
Step 950
950
#002D30
oklch(27% 0.046 201.8)
#40D3DF 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) | #C2CAE0 | 0.120 |
| Deuteranopia (no green cones) | #ACB9E0 | 0.112 |
| Tritanopia (no blue cones) | #00DBD6 | 0.032 |
| Achromatopsia (no color) | #C0C0C0 | 0.121 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #40D3DF
#40D3DF
oklch(79.6% 0.121 203.1)
- #FF9E99
#FF9E99
oklch(79.7% 0.117 23.2)
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 #40D3DF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Aqua Blue #02D8E9 ΔE 0.019
- Medium Turquoise #48D1CC ΔE 0.026
- Dark Turquoise #00CED1 ΔE 0.030
- Vivid Sky Blue #4CC9F0 ΔE 0.043
- Turquoise #40E0D0 ΔE 0.048
- Bright Sky Blue #02CCFE ΔE 0.056
- Sky Blue #87CEEB ΔE 0.058
- Seafoam Blue #78D1B6 ΔE 0.063
Use #40D3DF 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.