#4288EB
Closest named color: Dark Sky Blue (#448EE4). oklch(63.1% 0.165 257.6), rgb(66, 136, 235).
Aa
Black text reads best on this color (5.95:1).
About this color
#4288EB is a medium-light, vivid blue. In OKLCH its lightness is 63%, its chroma 0.165 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.021 away. Black text reads best on it, at 5.95:1.
| Hue family | Blues |
| Lightness | medium-light (63%) |
| Chroma | vivid (0.165) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 5.95:1 |
| White text | 3.52:1 |
Values
| HEX | #4288EB |
| RGB | rgb(66, 136, 235) |
| HSL | hsl(215, 81%, 59%) |
| OKLCH | oklch(63.1% 0.165 257.6) |
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 #4288EB | 3.52:1 | AA large text | Lc -68.0 | Content text, not long reading |
| Black text on #4288EB | 5.95:1 | AA | Lc 41.6 | Non-text elements, placeholder text |
| #4288EB text on white | 3.52:1 | AA large text | Lc 62.5 | Content text, not long reading |
| #4288EB text on black | 5.95:1 | 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
#E0EBFA
oklch(93.6% 0.024 256.1)
-
Step 200
200
#C7DBF7
oklch(88.5% 0.044 256.8)
-
Step 300
300
#A0C3F5
oklch(80.9% 0.081 257.3)
-
Step 400
400
#6BA2F0
oklch(70.7% 0.129 257.2)
-
Step 500
500 (this color)
#4288EB
oklch(63.1% 0.165 257.6)
-
Step 600
600
#1F6FD9
oklch(55.5% 0.179 257.6)
-
Step 700
700
#105CBD
oklch(49.1% 0.168 257.7)
-
Step 800
800
#124C99
oklch(42.7% 0.139 257.6)
-
Step 900
900
#174079
oklch(37.6% 0.107 257.5)
-
Step 950
950
#0F2647
oklch(27% 0.068 257.7)
#4288EB 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) | #5891EF | 0.034 |
| Deuteranopia (no green cones) | #3A81E9 | 0.021 |
| Tritanopia (no blue cones) | #009FAE | 0.129 |
| Achromatopsia (no color) | #888888 | 0.165 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4288EB
#4288EB
oklch(63.1% 0.165 257.6)
- #B57D00
#B57D00
oklch(63.1% 0.132 77.3)
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 #4288EB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.021
- Soft Blue #6488EA ΔE 0.033
- Dodger Blue #1E90FF ΔE 0.035
- Chefchaouen Blue #4895EF ΔE 0.036
- Cornflower Blue #6495ED ΔE 0.051
- Clear Blue #247AFD ΔE 0.053
- Cornflower #6A79F7 ΔE 0.056
- Water Blue #0E87CC ΔE 0.056
Use #4288EB 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.