#288ACB
Closest named color: Water Blue (#0E87CC). oklch(60.9% 0.132 243.2), rgb(40, 138, 203).
Aa
Black text reads best on this color (5.58:1).
About this color
#288ACB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 61%, its chroma 0.132 and its hue 243°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.014 away. Black text reads best on it, at 5.58:1.
| Hue family | Blues |
| Lightness | medium-dark (61%) |
| Chroma | moderately saturated (0.132) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.58:1 |
| White text | 3.75:1 |
Values
| HEX | #288ACB |
| RGB | rgb(40, 138, 203) |
| HSL | hsl(204, 67%, 48%) |
| OKLCH | oklch(60.9% 0.132 243.2) |
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 #288ACB | 3.75:1 | AA large text | Lc -70.2 | Content text, not long reading |
| Black text on #288ACB | 5.58:1 | AA | Lc 39.4 | Non-text elements, placeholder text |
| #288ACB text on white | 3.75:1 | AA large text | Lc 64.7 | Content text, not long reading |
| #288ACB text on black | 5.58:1 | AA | Lc -37.0 | 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
#E0ECF6
oklch(93.7% 0.019 243)
-
Step 200
200
#C6DCEF
oklch(88.4% 0.035 244.2)
-
Step 300
300
#9DC6E8
oklch(80.9% 0.065 243.7)
-
Step 400
400
#64A8DC
oklch(70.7% 0.103 243)
-
Step 500
500 (this color)
#288ACB
oklch(60.9% 0.132 243.2)
-
Step 600
600
#007ABB
oklch(55.7% 0.134 242.9)
-
Step 700
700
#00669E
oklch(49% 0.119 243.2)
-
Step 800
800
#005483
oklch(42.8% 0.104 243)
-
Step 900
900
#09456B
oklch(37.6% 0.086 243.5)
-
Step 950
950
#0A293F
oklch(27.1% 0.054 243.5)
#288ACB 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) | #6B8CCE | 0.059 |
| Deuteranopia (no green cones) | #557DCA | 0.045 |
| Tritanopia (no blue cones) | #009AA1 | 0.091 |
| Achromatopsia (no color) | #848484 | 0.132 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #288ACB
#288ACB
oklch(60.9% 0.132 243.2)
- #B96F16
#B96F16
oklch(61% 0.132 63.5)
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 #288ACB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.014
- Cool Blue #4984B8 ΔE 0.034
- Steel Blue #4682B4 ΔE 0.039
- Blue NCS #118AB2 ΔE 0.041
- Dark Sky Blue #448EE4 ΔE 0.045
- Windows Blue #3778BF ΔE 0.049
- Off Blue #5684AE ΔE 0.052
- Dusty Blue #5A86AD ΔE 0.055
Use #288ACB 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.