#42BFEF
Closest named color: Deep Sky Blue (#00BFFF). oklch(75.6% 0.127 228), rgb(66, 191, 239).
Aa
Black text reads best on this color (9.93:1).
About this color
#42BFEF is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 76%, its chroma 0.127 and its hue 228°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.028 away. Black text reads best on it, at 9.93:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (76%) |
| Chroma | moderately saturated (0.127) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 9.93:1 |
| White text | 2.11:1 |
Values
| HEX | #42BFEF |
| RGB | rgb(66, 191, 239) |
| HSL | hsl(197, 84%, 60%) |
| OKLCH | oklch(75.6% 0.127 228) |
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 #42BFEF | 2.11:1 | Fails | Lc -45.7 | Large or bold text, headings |
| Black text on #42BFEF | 9.93:1 | AAA | Lc 62.9 | Content text, not long reading |
| #42BFEF text on white | 2.11:1 | Fails | Lc 41.1 | Non-text elements, placeholder text |
| #42BFEF text on black | 9.93:1 | AAA | Lc -61.2 | 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 400.
-
Step 50
50
#EFF7FB
oklch(97.1% 0.01 228.9)
-
Step 100
100
#DBEDF6
oklch(93.5% 0.023 229.1)
-
Step 200
200
#BCE0F0
oklch(88.6% 0.044 226.6)
-
Step 300
300
#89CBE9
oklch(80.9% 0.079 228.3)
-
Step 400
400 (this color)
#42BFEF
oklch(75.6% 0.127 228)
-
Step 500
500
#0097C4
oklch(63.2% 0.123 228.1)
-
Step 600
600
#007FA5
oklch(55.7% 0.108 227.8)
-
Step 700
700
#006A8B
oklch(49% 0.096 228.3)
-
Step 800
800
#005773
oklch(42.7% 0.084 228.5)
-
Step 900
900
#004960
oklch(37.8% 0.073 227.3)
-
Step 950
950
#002B3B
oklch(27% 0.053 228.8)
#42BFEF 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) | #A6BCF1 | 0.092 |
| Deuteranopia (no green cones) | #8EABEE | 0.079 |
| Tritanopia (no blue cones) | #00CDCF | 0.072 |
| Achromatopsia (no color) | #B2B2B2 | 0.127 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42BFEF
#42BFEF
oklch(75.6% 0.127 228)
- #F19666
#F19666
oklch(75.7% 0.127 47.9)
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 #42BFEF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.028
- Vivid Sky Blue #4CC9F0 ΔE 0.029
- Bright Sky Blue #02CCFE ΔE 0.037
- Lightblue #7BC8F6 ΔE 0.054
- Sky #82CAFC ΔE 0.064
- Carolina Blue #8AB8FE ΔE 0.068
- Dark Turquoise #00CED1 ΔE 0.072
- Aqua Blue #02D8E9 ΔE 0.073
Use #42BFEF 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.