#288BC4
Closest named color: Water Blue (#0E87CC). oklch(60.8% 0.123 239.5), rgb(40, 139, 196).
Aa
Black text reads best on this color (5.58:1).
About this color
#288BC4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 61%, its chroma 0.123 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.021 away. Black text reads best on it, at 5.58:1.
| Hue family | Blues |
| Lightness | medium-dark (61%) |
| Chroma | moderately saturated (0.123) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.58:1 |
| White text | 3.76:1 |
Values
| HEX | #288BC4 |
| RGB | rgb(40, 139, 196) |
| HSL | hsl(202, 66%, 46%) |
| OKLCH | oklch(60.8% 0.123 239.5) |
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 #288BC4 | 3.76:1 | AA large text | Lc -70.3 | Content text, not long reading |
| Black text on #288BC4 | 5.58:1 | AA | Lc 39.3 | Non-text elements, placeholder text |
| #288BC4 text on white | 3.76:1 | AA large text | Lc 64.8 | Content text, not long reading |
| #288BC4 text on black | 5.58:1 | AA | Lc -36.9 | 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
#F1F6FA
oklch(97.1% 0.008 241.7)
-
Step 100
100
#E0ECF5
oklch(93.7% 0.018 240)
-
Step 200
200
#C6DDED
oklch(88.5% 0.033 238.2)
-
Step 300
300
#9EC7E4
oklch(81% 0.06 239.3)
-
Step 400
400
#65A9D6
oklch(70.7% 0.096 239.1)
-
Step 500
500 (this color)
#288BC4
oklch(60.8% 0.123 239.5)
-
Step 600
600
#007BB5
oklch(55.6% 0.127 239.8)
-
Step 700
700
#006799
oklch(49% 0.112 240)
-
Step 800
800
#00557E
oklch(42.8% 0.097 239.2)
-
Step 900
900
#0A4667
oklch(37.6% 0.08 239.6)
-
Step 950
950
#0A293D
oklch(26.9% 0.052 241)
#288BC4 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) | #708BC7 | 0.065 |
| Deuteranopia (no green cones) | #5B7DC3 | 0.052 |
| Tritanopia (no blue cones) | #00999F | 0.081 |
| Achromatopsia (no color) | #848484 | 0.123 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #288BC4
#288BC4
oklch(60.8% 0.123 239.5)
- #B76E2A
#B76E2A
oklch(60.7% 0.123 59.5)
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 #288BC4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.021
- Cool Blue #4984B8 ΔE 0.029
- Blue NCS #118AB2 ΔE 0.030
- Steel Blue #4682B4 ΔE 0.033
- Off Blue #5684AE ΔE 0.045
- Dusty Blue #5A86AD ΔE 0.048
- Faded Blue #658CBB ΔE 0.052
- Windows Blue #3778BF ΔE 0.052
Use #288BC4 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.