#577CB0
Closest named color: Steel Blue (#4682B4). oklch(58.1% 0.091 257), rgb(87, 124, 176).
Aa
Black text reads best on this color (4.91:1).
About this color
#577CB0 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.091 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Steel Blue (#4682B4), ΔE 0.022 away. Black text reads best on it, at 4.91:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.091) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 4.91:1 |
| White text | 4.27:1 |
Values
| HEX | #577CB0 |
| RGB | rgb(87, 124, 176) |
| HSL | hsl(215, 36%, 52%) |
| OKLCH | oklch(58.1% 0.091 257) |
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 #577CB0 | 4.27:1 | AA large text | Lc -74.9 | Content text, not long reading |
| Black text on #577CB0 | 4.91:1 | AA | Lc 34.6 | Non-text elements, placeholder text |
| #577CB0 text on white | 4.27:1 | AA large text | Lc 69.4 | Content text, not long reading |
| #577CB0 text on black | 4.91:1 | 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
#F3F6F9
oklch(97.2% 0.005 247.9)
-
Step 100
100
#E5EAF2
oklch(93.6% 0.012 259.8)
-
Step 200
200
#D0DAE8
oklch(88.5% 0.022 256.7)
-
Step 300
300
#B0C2DB
oklch(80.8% 0.041 256.6)
-
Step 400
400
#87A2CA
oklch(70.6% 0.066 258.1)
-
Step 500
500
#698BBC
oklch(63.1% 0.084 257.5)
-
Step 600
600 (this color)
#577CB0
oklch(58.1% 0.091 257)
-
Step 700
700
#416290
oklch(49.2% 0.084 256.9)
-
Step 800
800
#355075
oklch(42.7% 0.07 256.5)
-
Step 900
900
#2F425E
oklch(37.6% 0.054 257.9)
-
Step 950
950
#1B2737
oklch(26.9% 0.034 255.8)
#577CB0 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) | #687FB2 | 0.024 |
| Deuteranopia (no green cones) | #5D77AF | 0.015 |
| Tritanopia (no blue cones) | #2D878E | 0.080 |
| Achromatopsia (no color) | #7A7A7A | 0.091 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #577CB0
#577CB0
oklch(58.1% 0.091 257)
- #997337
#997337
oklch(58.1% 0.091 76.7)
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 #577CB0, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Steel Blue #4682B4 ΔE 0.022
- Off Blue #5684AE ΔE 0.024
- Cool Blue #4984B8 ΔE 0.025
- Dusty Blue #5A86AD ΔE 0.031
- Stormy Blue #507B9C ΔE 0.033
- Cerulean #457B9D ΔE 0.037
- Dull Blue #49759C ΔE 0.039
- Windows Blue #3778BF ΔE 0.042
Use #577CB0 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.