#577EB9
Closest named color: Cool Blue (#4984B8). oklch(59% 0.101 258.4), rgb(87, 126, 185).
Aa
Black text reads best on this color (5.09:1).
About this color
#577EB9 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.101 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.021 away. Black text reads best on it, at 5.09:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.101) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.09:1 |
| White text | 4.12:1 |
Values
| HEX | #577EB9 |
| RGB | rgb(87, 126, 185) |
| HSL | hsl(216, 41%, 53%) |
| OKLCH | oklch(59% 0.101 258.4) |
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 #577EB9 | 4.12:1 | AA large text | Lc -73.7 | Content text, not long reading |
| Black text on #577EB9 | 5.09:1 | AA | Lc 35.8 | Non-text elements, placeholder text |
| #577EB9 text on white | 4.12:1 | AA large text | Lc 68.2 | Content text, not long reading |
| #577EB9 text on black | 5.09:1 | AA | Lc -33.4 | 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
#AFC2DF
oklch(80.9% 0.046 258.8)
-
Step 400
400
#85A2CE
oklch(70.7% 0.072 258.6)
-
Step 500
500
#668BC2
oklch(63.2% 0.093 258.1)
-
Step 600
600 (this color)
#577EB9
oklch(59% 0.101 258.4)
-
Step 700
700
#3E6196
oklch(49.1% 0.095 258.5)
-
Step 800
800
#344F79
oklch(42.6% 0.078 258.9)
-
Step 900
900
#2D4262
oklch(37.7% 0.061 258.6)
-
Step 950
950
#1B2739
oklch(27.1% 0.038 258.3)
#577EB9 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) | #6782BC | 0.024 |
| Deuteranopia (no green cones) | #5B79B8 | 0.014 |
| Tritanopia (no blue cones) | #238B93 | 0.090 |
| Achromatopsia (no color) | #7D7D7D | 0.101 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #577EB9
#577EB9
oklch(59% 0.101 258.4)
- #9E752E
#9E752E
oklch(59% 0.101 78.1)
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 #577EB9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.021
- Steel Blue #4682B4 ΔE 0.022
- Off Blue #5684AE ΔE 0.027
- Dusty Blue #5A86AD ΔE 0.034
- Windows Blue #3778BF ΔE 0.039
- Faded Blue #658CBB ΔE 0.045
- Stormy Blue #507B9C ΔE 0.046
- Cerulean #457B9D ΔE 0.049
Use #577EB9 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.