#42BFEB
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(75.5% 0.124 225.8), rgb(66, 191, 235).
Aa
Black text reads best on this color (9.88:1).
About this color
#42BFEB is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 75%, its chroma 0.124 and its hue 226°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.029 away. Black text reads best on it, at 9.88:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (75%) |
| Chroma | moderately saturated (0.124) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 9.88:1 |
| White text | 2.12:1 |
Values
| HEX | #42BFEB |
| RGB | rgb(66, 191, 235) |
| HSL | hsl(196, 81%, 59%) |
| OKLCH | oklch(75.5% 0.124 225.8) |
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 #42BFEB | 2.12:1 | Fails | Lc -45.9 | Large or bold text, headings |
| Black text on #42BFEB | 9.88:1 | AAA | Lc 62.6 | Content text, not long reading |
| #42BFEB text on white | 2.12:1 | Fails | Lc 41.3 | Non-text elements, placeholder text |
| #42BFEB text on black | 9.88:1 | AAA | Lc -61.0 | 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 400.
-
Step 50
50
#EFF7FB
oklch(97.1% 0.01 228.9)
-
Step 100
100
#DBEDF5
oklch(93.5% 0.022 226.1)
-
Step 200
200
#BCE0EF
oklch(88.6% 0.043 225)
-
Step 300
300
#89CCE7
oklch(81% 0.078 225.3)
-
Step 400
400 (this color)
#42BFEB
oklch(75.5% 0.124 225.8)
-
Step 500
500
#0097C1
oklch(63% 0.121 226.4)
-
Step 600
600
#007FA2
oklch(55.5% 0.106 225.7)
-
Step 700
700
#006B89
oklch(49.1% 0.094 225.7)
-
Step 800
800
#005771
oklch(42.6% 0.082 226.6)
-
Step 900
900
#00495F
oklch(37.8% 0.072 226.2)
-
Step 950
950
#002B39
oklch(26.9% 0.051 225.5)
#42BFEB 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) | #A7BBED | 0.094 |
| Deuteranopia (no green cones) | #90ABEA | 0.081 |
| Tritanopia (no blue cones) | #00CCCD | 0.068 |
| Achromatopsia (no color) | #B2B2B2 | 0.124 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42BFEB
#42BFEB
oklch(75.5% 0.124 225.8)
- #F0956A
#F0956A
oklch(75.5% 0.124 45.6)
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 #42BFEB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.029
- Deep Sky Blue #00BFFF ΔE 0.033
- Bright Sky Blue #02CCFE ΔE 0.039
- Lightblue #7BC8F6 ΔE 0.055
- Sky #82CAFC ΔE 0.066
- Dark Turquoise #00CED1 ΔE 0.067
- Turquoise Blue #06B1C4 ΔE 0.069
- Aqua Blue #02D8E9 ΔE 0.070
Use #42BFEB 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.