#4287EF
Closest named color: Dark Sky Blue (#448EE4). oklch(63.1% 0.171 258.6), rgb(66, 135, 239).
Aa
Black text reads best on this color (5.94:1).
About this color
#4287EF is a medium-light, vivid blue. In OKLCH its lightness is 63%, its chroma 0.171 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.027 away. Black text reads best on it, at 5.94:1.
| Hue family | Blues |
| Lightness | medium-light (63%) |
| Chroma | vivid (0.171) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 5.94:1 |
| White text | 3.53:1 |
Values
| HEX | #4287EF |
| RGB | rgb(66, 135, 239) |
| HSL | hsl(216, 84%, 60%) |
| OKLCH | oklch(63.1% 0.171 258.6) |
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 #4287EF | 3.53:1 | AA large text | Lc -68.0 | Content text, not long reading |
| Black text on #4287EF | 5.94:1 | AA | Lc 41.5 | Non-text elements, placeholder text |
| #4287EF text on white | 3.53:1 | AA large text | Lc 62.5 | Content text, not long reading |
| #4287EF text on black | 5.94:1 | AA | Lc -39.2 | Non-text elements, placeholder text |
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 500.
-
Step 50
50
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E0EBFB
oklch(93.7% 0.025 257.6)
-
Step 200
200
#C7DBF9
oklch(88.6% 0.047 258.4)
-
Step 300
300
#A0C2F7
oklch(80.8% 0.084 259.1)
-
Step 400
400
#6BA1F3
oklch(70.7% 0.134 258.5)
-
Step 500
500 (this color)
#4287EF
oklch(63.1% 0.171 258.6)
-
Step 600
600
#206EDD
oklch(55.6% 0.185 258.5)
-
Step 700
700
#115BC0
oklch(49.1% 0.173 258.5)
-
Step 800
800
#134B9B
oklch(42.7% 0.143 258.6)
-
Step 900
900
#173F7C
oklch(37.6% 0.113 258.9)
-
Step 950
950
#0F2648
oklch(27.1% 0.07 258.2)
#4287EF 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) | #5391F3 | 0.032 |
| Deuteranopia (no green cones) | #3281ED | 0.021 |
| Tritanopia (no blue cones) | #009FAF | 0.134 |
| Achromatopsia (no color) | #888888 | 0.171 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4287EF
#4287EF
oklch(63.1% 0.171 258.6)
- #B47E00
#B47E00
oklch(63.1% 0.131 78.5)
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 #4287EF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.027
- Dodger Blue #1E90FF ΔE 0.033
- Soft Blue #6488EA ΔE 0.034
- Chefchaouen Blue #4895EF ΔE 0.039
- Clear Blue #247AFD ΔE 0.048
- Cornflower #6A79F7 ΔE 0.052
- Cornflower Blue #6495ED ΔE 0.053
- Water Blue #0E87CC ΔE 0.062
Use #4287EF 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.