#577FB9
Closest named color: Cool Blue (#4984B8). oklch(59.2% 0.1 257.6), rgb(87, 127, 185).
Aa
Black text reads best on this color (5.14:1).
About this color
#577FB9 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.100 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.019 away. Black text reads best on it, at 5.14:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.100) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.14:1 |
| White text | 4.08:1 |
Values
| HEX | #577FB9 |
| RGB | rgb(87, 127, 185) |
| HSL | hsl(216, 41%, 53%) |
| OKLCH | oklch(59.2% 0.1 257.6) |
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 #577FB9 | 4.08:1 | AA large text | Lc -73.4 | Content text, not long reading |
| Black text on #577FB9 | 5.14:1 | AA | Lc 36.2 | Non-text elements, placeholder text |
| #577FB9 text on white | 4.08:1 | AA large text | Lc 67.9 | Content text, not long reading |
| #577FB9 text on black | 5.14:1 | 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 600.
-
Step 50
50
#F3F6FA
oklch(97.2% 0.006 255.5)
-
Step 100
100
#E4EAF3
oklch(93.5% 0.014 258.3)
-
Step 200
200
#CFDAEA
oklch(88.5% 0.025 257.6)
-
Step 300
300
#AFC2DE
oklch(80.9% 0.045 258)
-
Step 400
400
#85A2CE
oklch(70.7% 0.072 258.6)
-
Step 500
500
#668BC1
oklch(63.1% 0.092 257.7)
-
Step 600
600 (this color)
#577FB9
oklch(59.2% 0.1 257.6)
-
Step 700
700
#3E6195
oklch(49.1% 0.093 258.1)
-
Step 800
800
#335079
oklch(42.8% 0.077 257.2)
-
Step 900
900
#2D4261
oklch(37.6% 0.06 258)
-
Step 950
950
#1A2739
oklch(27% 0.038 256.7)
#577FB9 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) | #6883BB | 0.025 |
| Deuteranopia (no green cones) | #5C79B8 | 0.017 |
| Tritanopia (no blue cones) | #238C94 | 0.089 |
| Achromatopsia (no color) | #7E7E7E | 0.100 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #577FB9
#577FB9
oklch(59.2% 0.1 257.6)
- #9F7630
#9F7630
oklch(59.3% 0.1 77.9)
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 #577FB9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.019
- Steel Blue #4682B4 ΔE 0.021
- Off Blue #5684AE ΔE 0.025
- Dusty Blue #5A86AD ΔE 0.031
- Windows Blue #3778BF ΔE 0.041
- Faded Blue #658CBB ΔE 0.042
- Stormy Blue #507B9C ΔE 0.046
- Cerulean #457B9D ΔE 0.049
Use #577FB9 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.