#288BBB
Closest named color: Blue NCS (#118AB2). oklch(60.3% 0.114 234.9), rgb(40, 139, 187).
Aa
Black text reads best on this color (5.50:1).
About this color
#288BBB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 60%, its chroma 0.114 and its hue 235°. Its hue sits on the cool side of the wheel. The nearest named color is Blue NCS (#118AB2), ΔE 0.017 away. Black text reads best on it, at 5.50:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.114) |
| Temperature | cool |
| Nearest name | Blue NCS (#118AB2) |
| Black text | 5.50:1 |
| White text | 3.81:1 |
Values
| HEX | #288BBB |
| RGB | rgb(40, 139, 187) |
| HSL | hsl(200, 65%, 45%) |
| OKLCH | oklch(60.3% 0.114 234.9) |
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 #288BBB | 3.81:1 | AA large text | Lc -70.8 | Content text, not long reading |
| Black text on #288BBB | 5.50:1 | AA | Lc 38.8 | Non-text elements, placeholder text |
| #288BBB text on white | 3.81:1 | AA large text | Lc 65.3 | Content text, not long reading |
| #288BBB text on black | 5.50:1 | AA | Lc -36.4 | 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
#E0ECF3
oklch(93.6% 0.016 233)
-
Step 200
200
#C6DDEB
oklch(88.5% 0.031 234.5)
-
Step 300
300
#9EC7E0
oklch(80.9% 0.056 235.2)
-
Step 400
400
#66AAD0
oklch(70.8% 0.089 234.4)
-
Step 500
500 (this color)
#288BBB
oklch(60.3% 0.114 234.9)
-
Step 600
600
#007DAE
oklch(55.7% 0.118 234.9)
-
Step 700
700
#006993
oklch(49.2% 0.104 234.9)
-
Step 800
800
#005679
oklch(42.8% 0.09 234.7)
-
Step 900
900
#0B4763
oklch(37.6% 0.074 235.1)
-
Step 950
950
#0A2A3A
oklch(27% 0.047 234.3)
#288BBB 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) | #748ABD | 0.070 |
| Deuteranopia (no green cones) | #607CBA | 0.058 |
| Tritanopia (no blue cones) | #00989B | 0.072 |
| Achromatopsia (no color) | #828282 | 0.114 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #288BBB
#288BBB
oklch(60.3% 0.114 234.9)
- #B56D38
#B56D38
oklch(60.4% 0.114 54.8)
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 #288BBB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blue NCS #118AB2 ΔE 0.017
- Cool Blue #4984B8 ΔE 0.027
- Steel Blue #4682B4 ΔE 0.029
- Water Blue #0E87CC ΔE 0.032
- Off Blue #5684AE ΔE 0.038
- Dusty Blue #5A86AD ΔE 0.041
- Teal Blue #01889F ΔE 0.047
- Faded Blue #658CBB ΔE 0.052
Use #288BBB 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.