#4288B3
Closest named color: Cool Blue (#4984B8). oklch(60% 0.096 238.3), rgb(66, 136, 179).
Aa
Black text reads best on this color (5.40:1).
About this color
#4288B3 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 60%, its chroma 0.096 and its hue 238°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.016 away. Black text reads best on it, at 5.40:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.096) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.40:1 |
| White text | 3.88:1 |
Values
| HEX | #4288B3 |
| RGB | rgb(66, 136, 179) |
| HSL | hsl(203, 46%, 48%) |
| OKLCH | oklch(60% 0.096 238.3) |
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 #4288B3 | 3.88:1 | AA large text | Lc -71.6 | Content text, not long reading |
| Black text on #4288B3 | 5.40:1 | AA | Lc 38.0 | Non-text elements, placeholder text |
| #4288B3 text on white | 3.88:1 | AA large text | Lc 66.1 | Content text, not long reading |
| #4288B3 text on black | 5.40:1 | AA | Lc -35.6 | 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
#F2F6F9
oklch(97.1% 0.006 239.8)
-
Step 100
100
#E2EBF2
oklch(93.5% 0.014 241)
-
Step 200
200
#CADCE9
oklch(88.5% 0.026 239.1)
-
Step 300
300
#A5C6DC
oklch(81% 0.047 237.4)
-
Step 400
400
#73A8CA
oklch(70.7% 0.075 237.4)
-
Step 500
500 (this color)
#4288B3
oklch(60% 0.096 238.3)
-
Step 600
600
#2A7BA9
oklch(55.6% 0.105 238.1)
-
Step 700
700
#1C6891
oklch(49.2% 0.097 237.7)
-
Step 800
800
#1A5576
oklch(42.8% 0.081 237.8)
-
Step 900
900
#1D465F
oklch(37.7% 0.063 238.4)
-
Step 950
950
#122938
oklch(27% 0.04 239.2)
#4288B3 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) | #7488B5 | 0.054 |
| Deuteranopia (no green cones) | #657CB2 | 0.046 |
| Tritanopia (no blue cones) | #009397 | 0.068 |
| Achromatopsia (no color) | #818181 | 0.096 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4288B3
#4288B3
oklch(60% 0.096 238.3)
- #AB7143
#AB7143
oklch(60% 0.096 58)
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 #4288B3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.016
- Steel Blue #4682B4 ΔE 0.018
- Off Blue #5684AE ΔE 0.020
- Dusty Blue #5A86AD ΔE 0.023
- Blue NCS #118AB2 ΔE 0.026
- Faded Blue #658CBB ΔE 0.041
- Cerulean #457B9D ΔE 0.044
- Stormy Blue #507B9C ΔE 0.044
Use #4288B3 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.