#557BD0
Closest named color: Windows Blue (#3778BF). oklch(59.5% 0.137 264.5), rgb(85, 123, 208).
Aa
Black text reads best on this color (5.13:1).
About this color
#557BD0 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 60%, its chroma 0.137 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.041 away. Black text reads best on it, at 5.13:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.137) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.13:1 |
| White text | 4.09:1 |
Values
| HEX | #557BD0 |
| RGB | rgb(85, 123, 208) |
| HSL | hsl(221, 57%, 57%) |
| OKLCH | oklch(59.5% 0.137 264.5) |
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 #557BD0 | 4.09:1 | AA large text | Lc -73.4 | Content text, not long reading |
| Black text on #557BD0 | 5.13:1 | AA | Lc 36.2 | Non-text elements, placeholder text |
| #557BD0 text on white | 4.09:1 | AA large text | Lc 67.9 | Content text, not long reading |
| #557BD0 text on black | 5.13:1 | AA | Lc -33.8 | 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
#F2F5FC
oklch(97% 0.01 267.4)
-
Step 100
100
#E3EAF7
oklch(93.6% 0.019 263)
-
Step 200
200
#CDD9F3
oklch(88.4% 0.038 265.8)
-
Step 300
300
#ABC1ED
oklch(80.9% 0.067 264.1)
-
Step 400
400
#7F9FE4
oklch(70.6% 0.108 264.7)
-
Step 500
500 (this color)
#557BD0
oklch(59.5% 0.137 264.5)
-
Step 600
600
#466ECA
oklch(55.6% 0.15 264.4)
-
Step 700
700
#385BAE
oklch(49% 0.139 264.6)
-
Step 800
800
#2E4B8D
oklch(42.6% 0.115 264.3)
-
Step 900
900
#293F71
oklch(37.7% 0.09 264.6)
-
Step 950
950
#182542
oklch(26.9% 0.057 264.6)
#557BD0 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) | #5683D3 | 0.022 |
| Deuteranopia (no green cones) | #4578CE | 0.020 |
| Tritanopia (no blue cones) | #008E9B | 0.120 |
| Achromatopsia (no color) | #7D7D7D | 0.137 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #557BD0
#557BD0
oklch(59.5% 0.137 264.5)
- #A07700
#A07700
oklch(59.4% 0.122 84.4)
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 #557BD0, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.041
- Cool Blue #4984B8 ΔE 0.051
- Water Blue #0E87CC ΔE 0.052
- Soft Blue #6488EA ΔE 0.053
- Dark Sky Blue #448EE4 ΔE 0.054
- Steel Blue #4682B4 ΔE 0.054
- Royal Blue #4169E1 ΔE 0.062
- Off Blue #5684AE ΔE 0.064
Use #557BD0 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.