#577BC7
Closest named color: Windows Blue (#3778BF). oklch(59.1% 0.124 263.8), rgb(87, 123, 199).
Aa
Black text reads best on this color (5.06:1).
About this color
#577BC7 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.124 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.036 away. Black text reads best on it, at 5.06:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.124) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.06:1 |
| White text | 4.14:1 |
Values
| HEX | #577BC7 |
| RGB | rgb(87, 123, 199) |
| HSL | hsl(221, 50%, 56%) |
| OKLCH | oklch(59.1% 0.124 263.8) |
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 #577BC7 | 4.14:1 | AA large text | Lc -73.9 | Content text, not long reading |
| Black text on #577BC7 | 5.06:1 | AA | Lc 35.7 | Non-text elements, placeholder text |
| #577BC7 text on white | 4.14:1 | AA large text | Lc 68.4 | Content text, not long reading |
| #577BC7 text on black | 5.06:1 | AA | Lc -33.3 | 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
#F3F5FB
oklch(97% 0.008 271.3)
-
Step 100
100
#E4EAF5
oklch(93.6% 0.016 262.8)
-
Step 200
200
#CFD9EE
oklch(88.4% 0.031 265.3)
-
Step 300
300
#AEC1E6
oklch(80.9% 0.056 263.7)
-
Step 400
400
#84A0D9
oklch(70.6% 0.09 264)
-
Step 500
500
#6688CE
oklch(63.1% 0.113 263.8)
-
Step 600
600 (this color)
#577BC7
oklch(59.1% 0.124 263.8)
-
Step 700
700
#3E5EA2
oklch(49.2% 0.116 263.7)
-
Step 800
800
#334D83
oklch(42.7% 0.095 263.5)
-
Step 900
900
#2D4069
oklch(37.6% 0.075 264.3)
-
Step 950
950
#1A263D
oklch(27% 0.046 262.7)
#577BC7 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) | #5C82CA | 0.021 |
| Deuteranopia (no green cones) | #4E78C5 | 0.014 |
| Tritanopia (no blue cones) | #088C97 | 0.112 |
| Achromatopsia (no color) | #7C7C7C | 0.124 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #577BC7
#577BC7
oklch(59.1% 0.124 263.8)
- #A07600
#A07600
oklch(59.2% 0.122 83.6)
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 #577BC7, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.036
- Cool Blue #4984B8 ΔE 0.040
- Steel Blue #4682B4 ΔE 0.043
- Off Blue #5684AE ΔE 0.052
- Water Blue #0E87CC ΔE 0.052
- Dusty Blue #5A86AD ΔE 0.057
- Faded Blue #658CBB ΔE 0.059
- Dark Sky Blue #448EE4 ΔE 0.060
Use #577BC7 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.