#42ADDF
Closest named color: Turquoise Blue (#06B1C4). oklch(70.7% 0.121 232.5), rgb(66, 173, 223).
Aa
Black text reads best on this color (8.27:1).
About this color
#42ADDF is a medium-light, moderately saturated blue. In OKLCH its lightness is 71%, its chroma 0.121 and its hue 233°. Its hue sits on the cool side of the wheel. The nearest named color is Turquoise Blue (#06B1C4), ΔE 0.051 away. Black text reads best on it, at 8.27:1.
| Hue family | Blues |
| Lightness | medium-light (71%) |
| Chroma | moderately saturated (0.121) |
| Temperature | cool |
| Nearest name | Turquoise Blue (#06B1C4) |
| Black text | 8.27:1 |
| White text | 2.53:1 |
Values
| HEX | #42ADDF |
| RGB | rgb(66, 173, 223) |
| HSL | hsl(199, 71%, 57%) |
| OKLCH | oklch(70.7% 0.121 232.5) |
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 #42ADDF | 2.53:1 | Fails | Lc -54.5 | Large or bold text, headings |
| Black text on #42ADDF | 8.27:1 | AAA | Lc 54.6 | Large or bold text, headings |
| #42ADDF text on white | 2.53:1 | Fails | Lc 49.4 | Large or bold text, headings |
| #42ADDF text on black | 8.27:1 | AAA | Lc -52.5 | Large or bold text, headings |
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 400.
-
Step 50
50
#EFF7FB
oklch(97.1% 0.01 228.9)
-
Step 100
100
#DCEDF6
oklch(93.6% 0.022 230.5)
-
Step 200
200
#BFDFF1
oklch(88.6% 0.042 232.6)
-
Step 300
300
#8FCAE9
oklch(81% 0.075 231.8)
-
Step 400
400 (this color)
#42ADDF
oklch(70.7% 0.121 232.5)
-
Step 500
500
#0095CA
oklch(63% 0.13 232.7)
-
Step 600
600
#007EAB
oklch(55.7% 0.114 232.4)
-
Step 700
700
#006990
oklch(49% 0.101 232.9)
-
Step 800
800
#005677
oklch(42.6% 0.088 233.1)
-
Step 900
900
#004864
oklch(37.8% 0.078 232.8)
-
Step 950
950
#002B3D
oklch(27.1% 0.055 231.9)
#42ADDF 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) | #94ABE1 | 0.078 |
| Deuteranopia (no green cones) | #7F9CDE | 0.067 |
| Tritanopia (no blue cones) | #00BABE | 0.073 |
| Achromatopsia (no color) | #A2A2A2 | 0.121 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42ADDF
#42ADDF
oklch(70.7% 0.121 232.5)
- #DB8A56
#DB8A56
oklch(70.7% 0.12 52.4)
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 #42ADDF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Turquoise Blue #06B1C4 ΔE 0.051
- Deep Sky Blue #00BFFF ΔE 0.058
- Greyblue #77A1B5 ΔE 0.070
- Chefchaouen Blue #4895EF ΔE 0.075
- Cornflower Blue #6495ED ΔE 0.076
- Vivid Sky Blue #4CC9F0 ΔE 0.078
- Bluegrey #85A3B2 ΔE 0.081
- Bright Sky Blue #02CCFE ΔE 0.085
Use #42ADDF 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.