#557DB5
Closest named color: Steel Blue (#4682B4). oklch(58.5% 0.098 256.9), rgb(85, 125, 181).
Aa
Black text reads best on this color (4.98:1).
About this color
#557DB5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.098 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Steel Blue (#4682B4), ΔE 0.020 away. Black text reads best on it, at 4.98:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.098) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 4.98:1 |
| White text | 4.21:1 |
Values
| HEX | #557DB5 |
| RGB | rgb(85, 125, 181) |
| HSL | hsl(215, 39%, 52%) |
| OKLCH | oklch(58.5% 0.098 256.9) |
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 #557DB5 | 4.21:1 | AA large text | Lc -74.4 | Content text, not long reading |
| Black text on #557DB5 | 4.98:1 | AA | Lc 35.2 | Non-text elements, placeholder text |
| #557DB5 text on white | 4.21:1 | AA large text | Lc 68.9 | Content text, not long reading |
| #557DB5 text on black | 4.98:1 | AA | Lc -32.7 | 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 600.
-
Step 50
50
#F3F6F9
oklch(97.2% 0.005 247.9)
-
Step 100
100
#E5EAF3
oklch(93.6% 0.013 262.4)
-
Step 200
200
#CFDAEA
oklch(88.5% 0.025 257.6)
-
Step 300
300
#AFC2DD
oklch(80.8% 0.044 257.1)
-
Step 400
400
#85A3CD
oklch(70.8% 0.07 256.8)
-
Step 500
500
#668BC0
oklch(63.1% 0.091 257.4)
-
Step 600
600 (this color)
#557DB5
oklch(58.5% 0.098 256.9)
-
Step 700
700
#3E6294
oklch(49.2% 0.091 256.8)
-
Step 800
800
#335078
oklch(42.8% 0.075 256.7)
-
Step 900
900
#2D4260
oklch(37.6% 0.058 257.3)
-
Step 950
950
#1B2738
oklch(27% 0.036 257.1)
#557DB5 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) | #6780B7 | 0.024 |
| Deuteranopia (no green cones) | #5B77B4 | 0.017 |
| Tritanopia (no blue cones) | #228991 | 0.086 |
| Achromatopsia (no color) | #7B7B7B | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #557DB5
#557DB5
oklch(58.5% 0.098 256.9)
- #9C7331
#9C7331
oklch(58.4% 0.097 76.5)
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 #557DB5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Steel Blue #4682B4 ΔE 0.020
- Cool Blue #4984B8 ΔE 0.021
- Off Blue #5684AE ΔE 0.025
- Dusty Blue #5A86AD ΔE 0.033
- Windows Blue #3778BF ΔE 0.038
- Stormy Blue #507B9C ΔE 0.040
- Cerulean #457B9D ΔE 0.043
- Flat Blue #3C73A8 ΔE 0.044
Use #557DB5 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.