#4288DC
Closest named color: Dark Sky Blue (#448EE4). oklch(62.2% 0.146 254.6), rgb(66, 136, 220).
Aa
Black text reads best on this color (5.78:1).
About this color
#4288DC is a medium-light, vivid blue. In OKLCH its lightness is 62%, its chroma 0.146 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.019 away. Black text reads best on it, at 5.78:1.
| Hue family | Blues |
| Lightness | medium-light (62%) |
| Chroma | vivid (0.146) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 5.78:1 |
| White text | 3.62:1 |
Values
| HEX | #4288DC |
| RGB | rgb(66, 136, 220) |
| HSL | hsl(213, 69%, 56%) |
| OKLCH | oklch(62.2% 0.146 254.6) |
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 #4288DC | 3.62:1 | AA large text | Lc -69.1 | Content text, not long reading |
| Black text on #4288DC | 5.78:1 | AA | Lc 40.5 | Non-text elements, placeholder text |
| #4288DC text on white | 3.62:1 | AA large text | Lc 63.6 | Content text, not long reading |
| #4288DC text on black | 5.78:1 | AA | Lc -38.1 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF8
oklch(93.6% 0.021 254.9)
-
Step 200
200
#C8DBF4
oklch(88.5% 0.04 255.3)
-
Step 300
300
#A2C4EE
oklch(81% 0.07 253.9)
-
Step 400
400
#6EA3E6
oklch(70.6% 0.114 254.8)
-
Step 500
500 (this color)
#4288DC
oklch(62.2% 0.146 254.6)
-
Step 600
600
#2273CD
oklch(55.6% 0.158 254.5)
-
Step 700
700
#1460B1
oklch(49.1% 0.147 254.5)
-
Step 800
800
#144F90
oklch(42.8% 0.122 254.4)
-
Step 900
900
#194272
oklch(37.7% 0.094 254.4)
-
Step 950
950
#102743
oklch(27% 0.06 254.6)
#4288DC 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) | #618EDF | 0.036 |
| Deuteranopia (no green cones) | #4A80DA | 0.021 |
| Tritanopia (no blue cones) | #009CA7 | 0.115 |
| Achromatopsia (no color) | #868686 | 0.146 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4288DC
#4288DC
oklch(62.2% 0.146 254.6)
- #B57900
#B57900
oklch(62.3% 0.132 74.4)
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 #4288DC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.019
- Water Blue #0E87CC ΔE 0.038
- Soft Blue #6488EA ΔE 0.041
- Chefchaouen Blue #4895EF ΔE 0.043
- Dodger Blue #1E90FF ΔE 0.054
- Cool Blue #4984B8 ΔE 0.054
- Cornflower Blue #6495ED ΔE 0.056
- Windows Blue #3778BF ΔE 0.060
Use #4288DC 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.