#42BBFE
Closest named color: Deep Sky Blue (#00BFFF). oklch(75.4% 0.142 237.6), rgb(66, 187, 254).
Aa
Black text reads best on this color (9.77:1).
About this color
#42BBFE is a medium-light, vivid blue. In OKLCH its lightness is 75%, its chroma 0.142 and its hue 238°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.019 away. Black text reads best on it, at 9.77:1.
| Hue family | Blues |
| Lightness | medium-light (75%) |
| Chroma | vivid (0.142) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 9.77:1 |
| White text | 2.14:1 |
Values
| HEX | #42BBFE |
| RGB | rgb(66, 187, 254) |
| HSL | hsl(201, 99%, 63%) |
| OKLCH | oklch(75.4% 0.142 237.6) |
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 #42BBFE | 2.14:1 | Fails | Lc -46.5 | Large or bold text, headings |
| Black text on #42BBFE | 9.77:1 | AAA | Lc 62.1 | Content text, not long reading |
| #42BBFE text on white | 2.14:1 | Fails | Lc 41.8 | Non-text elements, placeholder text |
| #42BBFE text on black | 9.77:1 | AAA | Lc -60.4 | 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
#EEF7FD
oklch(97.1% 0.013 236.6)
-
Step 100
100
#DBEDF9
oklch(93.6% 0.025 236.8)
-
Step 200
200
#BCDFF6
oklch(88.6% 0.049 236.9)
-
Step 300
300
#88CAF3
oklch(81% 0.089 236.6)
-
Step 400
400 (this color)
#42BBFE
oklch(75.4% 0.142 237.6)
-
Step 500
500
#0094D3
oklch(63.2% 0.139 237.5)
-
Step 600
600
#007CB2
oklch(55.6% 0.123 237.7)
-
Step 700
700
#006896
oklch(49.1% 0.108 237.6)
-
Step 800
800
#00557C
oklch(42.7% 0.094 237.9)
-
Step 900
900
#004768
oklch(37.7% 0.083 237.5)
-
Step 950
950
#002A40
oklch(27% 0.06 237.8)
#42BBFE 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) | #9BBBFF | 0.080 |
| Deuteranopia (no green cones) | #82A9FD | 0.066 |
| Tritanopia (no blue cones) | #00CCD2 | 0.093 |
| Achromatopsia (no color) | #B1B1B1 | 0.143 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42BBFE
#42BBFE
oklch(75.4% 0.142 237.6)
- #F2964A
#F2964A
oklch(75.4% 0.143 57.6)
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 #42BBFE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.019
- Bright Sky Blue #02CCFE ΔE 0.047
- Vivid Sky Blue #4CC9F0 ΔE 0.049
- Carolina Blue #8AB8FE ΔE 0.060
- Lightblue #7BC8F6 ΔE 0.062
- Sky #82CAFC ΔE 0.070
- Light Sky Blue #87CEFA ΔE 0.082
- Sky Blue #87CEEB ΔE 0.089
Use #42BBFE 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.