#288DE5
Closest named color: Dark Sky Blue (#448EE4). oklch(63.1% 0.16 249.9), rgb(40, 141, 229).
Aa
Black text reads best on this color (6.03:1).
About this color
#288DE5 is a medium-light, vivid blue. In OKLCH its lightness is 63%, its chroma 0.160 and its hue 250°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.018 away. Black text reads best on it, at 6.03:1.
| Hue family | Blues |
| Lightness | medium-light (63%) |
| Chroma | vivid (0.160) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 6.03:1 |
| White text | 3.48:1 |
Values
| HEX | #288DE5 |
| RGB | rgb(40, 141, 229) |
| HSL | hsl(208, 78%, 53%) |
| OKLCH | oklch(63.1% 0.16 249.9) |
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 #288DE5 | 3.48:1 | AA large text | Lc -67.3 | Content text, not long reading |
| Black text on #288DE5 | 6.03:1 | AA | Lc 42.2 | Non-text elements, placeholder text |
| #288DE5 text on white | 3.48:1 | AA large text | Lc 61.9 | Content text, not long reading |
| #288DE5 text on black | 6.03:1 | AA | Lc -39.8 | 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
#F0F6FC
oklch(97% 0.01 247.9)
-
Step 100
100
#DFEBF9
oklch(93.5% 0.023 252.2)
-
Step 200
200
#C4DCF5
oklch(88.5% 0.043 249.4)
-
Step 300
300
#9AC5F2
oklch(80.9% 0.079 250)
-
Step 400
400
#5FA6EB
oklch(70.8% 0.124 249.4)
-
Step 500
500 (this color)
#288DE5
oklch(63.1% 0.16 249.9)
-
Step 600
600
#0076CA
oklch(55.7% 0.156 249.7)
-
Step 700
700
#0063AB
oklch(49.2% 0.138 249.7)
-
Step 800
800
#00518D
oklch(42.7% 0.12 249.5)
-
Step 900
900
#034376
oklch(37.7% 0.104 250)
-
Step 950
950
#072845
oklch(27.1% 0.066 249.3)
#288DE5 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) | #6292E9 | 0.050 |
| Deuteranopia (no green cones) | #4482E3 | 0.031 |
| Tritanopia (no blue cones) | #00A2AE | 0.116 |
| Achromatopsia (no color) | #898989 | 0.160 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #288DE5
#288DE5
oklch(63.1% 0.16 249.9)
- #BD7800
#BD7800
oklch(63.1% 0.137 69.9)
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 #288DE5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.018
- Chefchaouen Blue #4895EF ΔE 0.035
- Dodger Blue #1E90FF ΔE 0.038
- Water Blue #0E87CC ΔE 0.042
- Soft Blue #6488EA ΔE 0.049
- Cornflower Blue #6495ED ΔE 0.056
- Clear Blue #247AFD ΔE 0.065
- Cool Blue #4984B8 ΔE 0.068
Use #288DE5 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.