#42ADFB
Closest named color: Deep Sky Blue (#00BFFF). oklch(72.1% 0.149 244.4), rgb(66, 173, 251).
Aa
Black text reads best on this color (8.60:1).
About this color
#42ADFB is a medium-light, vivid blue. In OKLCH its lightness is 72%, its chroma 0.149 and its hue 244°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.048 away. Black text reads best on it, at 8.60:1.
| Hue family | Blues |
| Lightness | medium-light (72%) |
| Chroma | vivid (0.149) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 8.60:1 |
| White text | 2.44:1 |
Values
| HEX | #42ADFB |
| RGB | rgb(66, 173, 251) |
| HSL | hsl(205, 96%, 62%) |
| OKLCH | oklch(72.1% 0.149 244.4) |
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 #42ADFB | 2.44:1 | Fails | Lc -52.7 | Large or bold text, headings |
| Black text on #42ADFB | 8.60:1 | AAA | Lc 56.3 | Large or bold text, headings |
| #42ADFB text on white | 2.44:1 | Fails | Lc 47.7 | Large or bold text, headings |
| #42ADFB text on black | 8.60:1 | AAA | Lc -54.4 | 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
#EFF7FD
oklch(97.2% 0.012 239.9)
-
Step 100
100
#DBECFB
oklch(93.5% 0.027 244.7)
-
Step 200
200
#BDDEFA
oklch(88.6% 0.052 244)
-
Step 300
300
#8CC8F9
oklch(81% 0.093 243.9)
-
Step 400
400 (this color)
#42ADFB
oklch(72.1% 0.149 244.4)
-
Step 500
500
#0090E0
oklch(63% 0.157 244.4)
-
Step 600
600
#0079BE
oklch(55.6% 0.139 244.6)
-
Step 700
700
#0066A0
oklch(49.2% 0.121 244)
-
Step 800
800
#005384
oklch(42.6% 0.106 244.3)
-
Step 900
900
#00456F
oklch(37.6% 0.093 244.3)
-
Step 950
950
#002944
oklch(27% 0.066 243.6)
#42ADFB 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) | #89AFFE | 0.065 |
| Deuteranopia (no green cones) | #6F9EFA | 0.049 |
| Tritanopia (no blue cones) | #00C0C9 | 0.105 |
| Achromatopsia (no color) | #A6A6A6 | 0.149 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42ADFB
#42ADFB
oklch(72.1% 0.149 244.4)
- #E48E29
#E48E29
oklch(72.1% 0.149 64.4)
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 #42ADFB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.048
- Chefchaouen Blue #4895EF ΔE 0.063
- Cornflower Blue #6495ED ΔE 0.064
- Carolina Blue #8AB8FE ΔE 0.074
- Bright Sky Blue #02CCFE ΔE 0.083
- Periwinkle Blue #8F99FB ΔE 0.084
- Dark Sky Blue #448EE4 ΔE 0.084
- Vivid Sky Blue #4CC9F0 ΔE 0.084
Use #42ADFB 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.