#288BDA
Closest named color: Water Blue (#0E87CC). oklch(62% 0.148 247.8), rgb(40, 139, 218).
Aa
Black text reads best on this color (5.79:1).
About this color
#288BDA is a medium-dark, vivid blue. In OKLCH its lightness is 62%, its chroma 0.148 and its hue 248°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.026 away. Black text reads best on it, at 5.79:1.
| Hue family | Blues |
| Lightness | medium-dark (62%) |
| Chroma | vivid (0.148) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.79:1 |
| White text | 3.62:1 |
Values
| HEX | #288BDA |
| RGB | rgb(40, 139, 218) |
| HSL | hsl(207, 71%, 51%) |
| OKLCH | oklch(62% 0.148 247.8) |
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 #288BDA | 3.62:1 | AA large text | Lc -68.9 | Content text, not long reading |
| Black text on #288BDA | 5.79:1 | AA | Lc 40.7 | Non-text elements, placeholder text |
| #288BDA text on white | 3.62:1 | AA large text | Lc 63.4 | Content text, not long reading |
| #288BDA text on black | 5.79:1 | AA | Lc -38.3 | 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
#DFEBF8
oklch(93.5% 0.022 250.2)
-
Step 200
200
#C5DCF3
oklch(88.5% 0.04 248.3)
-
Step 300
300
#9CC5EE
oklch(80.8% 0.073 248.7)
-
Step 400
400
#62A6E5
oklch(70.6% 0.116 248)
-
Step 500
500 (this color)
#288BDA
oklch(62% 0.148 247.8)
-
Step 600
600
#0077C5
oklch(55.6% 0.149 247.9)
-
Step 700
700
#0064A7
oklch(49.1% 0.132 247.9)
-
Step 800
800
#00528A
oklch(42.8% 0.115 247.8)
-
Step 900
900
#064472
oklch(37.7% 0.097 247.9)
-
Step 950
950
#082843
oklch(27% 0.062 248.2)
#288BDA 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) | #658FDD | 0.053 |
| Deuteranopia (no green cones) | #4B7FD8 | 0.036 |
| Tritanopia (no blue cones) | #009EA8 | 0.106 |
| Achromatopsia (no color) | #868686 | 0.148 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #288BDA
#288BDA
oklch(62% 0.148 247.8)
- #BB7400
#BB7400
oklch(62.1% 0.136 68.1)
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 #288BDA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.026
- Dark Sky Blue #448EE4 ΔE 0.026
- Chefchaouen Blue #4895EF ΔE 0.047
- Cool Blue #4984B8 ΔE 0.053
- Dodger Blue #1E90FF ΔE 0.055
- Soft Blue #6488EA ΔE 0.057
- Steel Blue #4682B4 ΔE 0.059
- Windows Blue #3778BF ΔE 0.060
Use #288BDA 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.