#4288B4
Closest named color: Cool Blue (#4984B8). oklch(60% 0.097 238.9), rgb(66, 136, 180).
Aa
Black text reads best on this color (5.41:1).
About this color
#4288B4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 60%, its chroma 0.097 and its hue 239°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.015 away. Black text reads best on it, at 5.41:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.097) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.41:1 |
| White text | 3.87:1 |
Values
| HEX | #4288B4 |
| RGB | rgb(66, 136, 180) |
| HSL | hsl(203, 46%, 48%) |
| OKLCH | oklch(60% 0.097 238.9) |
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 #4288B4 | 3.87:1 | AA large text | Lc -71.5 | Content text, not long reading |
| Black text on #4288B4 | 5.41:1 | AA | Lc 38.0 | Non-text elements, placeholder text |
| #4288B4 text on white | 3.87:1 | AA large text | Lc 66.0 | Content text, not long reading |
| #4288B4 text on black | 5.41:1 | 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
#73A8CB
oklch(70.8% 0.076 238.2)
-
Step 500
500 (this color)
#4288B4
oklch(60% 0.097 238.9)
-
Step 600
600
#2A7BAA
oklch(55.6% 0.106 238.7)
-
Step 700
700
#1C6792
oklch(49% 0.098 239.3)
-
Step 800
800
#1A5476
oklch(42.6% 0.081 239)
-
Step 900
900
#1D4660
oklch(37.8% 0.064 239.4)
-
Step 950
950
#122938
oklch(27% 0.04 239.2)
#4288B4 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) | #7488B6 | 0.054 |
| Deuteranopia (no green cones) | #647CB3 | 0.045 |
| Tritanopia (no blue cones) | #009397 | 0.070 |
| Achromatopsia (no color) | #818181 | 0.097 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4288B4
#4288B4
oklch(60% 0.097 238.9)
- #AB7141
#AB7141
oklch(60% 0.097 59)
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 #4288B4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.015
- Steel Blue #4682B4 ΔE 0.017
- Off Blue #5684AE ΔE 0.020
- Dusty Blue #5A86AD ΔE 0.023
- Blue NCS #118AB2 ΔE 0.026
- Faded Blue #658CBB ΔE 0.040
- Water Blue #0E87CC ΔE 0.044
- Cerulean #457B9D ΔE 0.045
Use #4288B4 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.