#577CB8
Closest named color: Steel Blue (#4682B4). oklch(58.5% 0.102 259.7), rgb(87, 124, 184).
Aa
Black text reads best on this color (4.98:1).
About this color
#577CB8 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.102 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 4.98:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.102) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 4.98:1 |
| White text | 4.21:1 |
Values
| HEX | #577CB8 |
| RGB | rgb(87, 124, 184) |
| HSL | hsl(217, 41%, 53%) |
| OKLCH | oklch(58.5% 0.102 259.7) |
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 #577CB8 | 4.21:1 | AA large text | Lc -74.5 | Content text, not long reading |
| Black text on #577CB8 | 4.98:1 | AA | Lc 35.1 | Non-text elements, placeholder text |
| #577CB8 text on white | 4.21:1 | AA large text | Lc 69.0 | Content text, not long reading |
| #577CB8 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
#F3F6FA
oklch(97.2% 0.006 255.5)
-
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
#B0C2DF
oklch(81% 0.046 259.9)
-
Step 400
400
#86A2CF
oklch(70.8% 0.073 259.8)
-
Step 500
500
#678AC2
oklch(63% 0.094 259.5)
-
Step 600
600 (this color)
#577CB8
oklch(58.5% 0.102 259.7)
-
Step 700
700
#406196
oklch(49.2% 0.094 259.5)
-
Step 800
800
#354F7A
oklch(42.7% 0.079 260)
-
Step 900
900
#2E4262
oklch(37.8% 0.061 259.5)
-
Step 950
950
#1B2739
oklch(27.1% 0.038 258.3)
#577CB8 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) | #6480BB | 0.021 |
| Deuteranopia (no green cones) | #5977B7 | 0.014 |
| Tritanopia (no blue cones) | #258992 | 0.090 |
| Achromatopsia (no color) | #7B7B7B | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #577CB8
#577CB8
oklch(58.5% 0.102 259.7)
- #9C742B
#9C742B
oklch(58.5% 0.102 79.1)
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 #577CB8, 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 0.025
- Off Blue #5684AE ΔE 0.031
- Windows Blue #3778BF ΔE 0.036
- Dusty Blue #5A86AD ΔE 0.038
- Stormy Blue #507B9C ΔE 0.045
- Flat Blue #3C73A8 ΔE 0.046
- Cerulean #457B9D ΔE 0.048
Use #577CB8 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.