#288BD3
Closest named color: Water Blue (#0E87CC). oklch(61.6% 0.14 245.5), rgb(40, 139, 211).
Aa
Black text reads best on this color (5.72:1).
About this color
#288BD3 is a medium-dark, vivid blue. In OKLCH its lightness is 62%, its chroma 0.140 and its hue 246°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.019 away. Black text reads best on it, at 5.72:1.
| Hue family | Blues |
| Lightness | medium-dark (62%) |
| Chroma | vivid (0.140) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.72:1 |
| White text | 3.66:1 |
Values
| HEX | #288BD3 |
| RGB | rgb(40, 139, 211) |
| HSL | hsl(205, 68%, 49%) |
| OKLCH | oklch(61.6% 0.14 245.5) |
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 #288BD3 | 3.66:1 | AA large text | Lc -69.3 | Content text, not long reading |
| Black text on #288BD3 | 5.72:1 | AA | Lc 40.2 | Non-text elements, placeholder text |
| #288BD3 text on white | 3.66:1 | AA large text | Lc 63.8 | Content text, not long reading |
| #288BD3 text on black | 5.72:1 | AA | Lc -37.8 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#DFECF7
oklch(93.7% 0.02 243.4)
-
Step 200
200
#C5DCF1
oklch(88.4% 0.038 245.8)
-
Step 300
300
#9CC6EB
oklch(80.9% 0.069 245.4)
-
Step 400
400
#63A7E1
oklch(70.7% 0.11 245.9)
-
Step 500
500 (this color)
#288BD3
oklch(61.6% 0.14 245.5)
-
Step 600
600
#0079C0
oklch(55.7% 0.141 245.3)
-
Step 700
700
#0065A2
oklch(49% 0.125 245.5)
-
Step 800
800
#005386
oklch(42.8% 0.108 245.3)
-
Step 900
900
#07456E
oklch(37.7% 0.091 245)
-
Step 950
950
#092941
oklch(27.2% 0.058 245.2)
#288BD3 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) | #698ED6 | 0.057 |
| Deuteranopia (no green cones) | #517FD2 | 0.040 |
| Tritanopia (no blue cones) | #009DA5 | 0.100 |
| Achromatopsia (no color) | #858585 | 0.140 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #288BD3
#288BD3
oklch(61.6% 0.14 245.5)
- #BC7100
#BC7100
oklch(61.7% 0.138 65.6)
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 #288BD3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.019
- Dark Sky Blue #448EE4 ΔE 0.034
- Cool Blue #4984B8 ΔE 0.044
- Steel Blue #4682B4 ΔE 0.049
- Blue NCS #118AB2 ΔE 0.053
- Chefchaouen Blue #4895EF ΔE 0.054
- Windows Blue #3778BF ΔE 0.055
- Faded Blue #658CBB ΔE 0.060
Use #288BD3 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.