#577BB5
Closest named color: Steel Blue (#4682B4). oklch(58.1% 0.099 259.6), rgb(87, 123, 181).
Aa
Black text reads best on this color (4.90:1).
About this color
#577BB5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.099 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Steel Blue (#4682B4), ΔE 0.025 away. Black text reads best on it, at 4.90:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.099) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 4.90:1 |
| White text | 4.28:1 |
Values
| HEX | #577BB5 |
| RGB | rgb(87, 123, 181) |
| HSL | hsl(217, 39%, 53%) |
| OKLCH | oklch(58.1% 0.099 259.6) |
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 #577BB5 | 4.28:1 | AA large text | Lc -75.0 | Content text, not long reading |
| Black text on #577BB5 | 4.90:1 | AA | Lc 34.6 | Non-text elements, placeholder text |
| #577BB5 text on white | 4.28:1 | AA large text | Lc 69.5 | Content text, not long reading |
| #577BB5 text on black | 4.90:1 | AA | Lc -32.2 | 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
#F3F6FA
oklch(97.2% 0.006 255.5)
-
Step 100
100
#E5EAF3
oklch(93.6% 0.013 262.4)
-
Step 200
200
#D0DAEA
oklch(88.6% 0.025 259.8)
-
Step 300
300
#B0C2DE
oklch(80.9% 0.044 259.2)
-
Step 400
400
#87A2CD
oklch(70.8% 0.07 259.6)
-
Step 500
500
#688AC1
oklch(63% 0.092 259.8)
-
Step 600
600 (this color)
#577BB5
oklch(58.1% 0.099 259.6)
-
Step 700
700
#416195
oklch(49.2% 0.092 259.7)
-
Step 800
800
#354F78
oklch(42.6% 0.076 259.2)
-
Step 900
900
#2E4261
oklch(37.7% 0.059 258.9)
-
Step 950
950
#1B2739
oklch(27.1% 0.038 258.3)
#577BB5 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) | #647FB7 | 0.021 |
| Deuteranopia (no green cones) | #5976B4 | 0.014 |
| Tritanopia (no blue cones) | #298890 | 0.088 |
| Achromatopsia (no color) | #7A7A7A | 0.099 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #577BB5
#577BB5
oklch(58.1% 0.099 259.6)
- #99732D
#99732D
oklch(58% 0.099 79.7)
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 #577BB5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Steel Blue #4682B4 ΔE 0.025
- Cool Blue #4984B8 ΔE 0.027
- Off Blue #5684AE ΔE 0.031
- Windows Blue #3778BF ΔE 0.037
- Dusty Blue #5A86AD ΔE 0.037
- Stormy Blue #507B9C ΔE 0.041
- Flat Blue #3C73A8 ΔE 0.043
- Cerulean #457B9D ΔE 0.044
Use #577BB5 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.