#577CBE
Closest named color: Cool Blue (#4984B8). oklch(58.8% 0.11 261.3), rgb(87, 124, 190).
Aa
Black text reads best on this color (5.03:1).
About this color
#577CBE is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.110 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.029 away. Black text reads best on it, at 5.03:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.110) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.03:1 |
| White text | 4.17:1 |
Values
| HEX | #577CBE |
| RGB | rgb(87, 124, 190) |
| HSL | hsl(218, 44%, 54%) |
| OKLCH | oklch(58.8% 0.11 261.3) |
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 #577CBE | 4.17:1 | AA large text | Lc -74.1 | Content text, not long reading |
| Black text on #577CBE | 5.03:1 | AA | Lc 35.5 | Non-text elements, placeholder text |
| #577CBE text on white | 4.17:1 | AA large text | Lc 68.6 | Content text, not long reading |
| #577CBE text on black | 5.03:1 | AA | Lc -33.0 | 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
#E5EAF4
oklch(93.6% 0.015 264.5)
-
Step 200
200
#CFDAEC
oklch(88.5% 0.028 260.3)
-
Step 300
300
#AFC2E1
oklch(81% 0.049 260.2)
-
Step 400
400
#85A1D3
oklch(70.7% 0.08 261.8)
-
Step 500
500
#6789C7
oklch(63.1% 0.102 261.9)
-
Step 600
600 (this color)
#577CBE
oklch(58.8% 0.11 261.3)
-
Step 700
700
#3F609A
oklch(49.2% 0.101 261)
-
Step 800
800
#344E7D
oklch(42.6% 0.085 261.5)
-
Step 900
900
#2D4165
oklch(37.6% 0.067 261.5)
-
Step 950
950
#1B263B
oklch(26.9% 0.042 262.7)
#577CBE 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) | #6281C1 | 0.020 |
| Deuteranopia (no green cones) | #5578BD | 0.012 |
| Tritanopia (no blue cones) | #1D8A94 | 0.098 |
| Achromatopsia (no color) | #7C7C7C | 0.110 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #577CBE
#577CBE
oklch(58.8% 0.11 261.3)
- #9E751F
#9E751F
oklch(58.9% 0.11 81.2)
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 #577CBE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.029
- Steel Blue #4682B4 ΔE 0.030
- Windows Blue #3778BF ΔE 0.035
- Off Blue #5684AE ΔE 0.038
- Dusty Blue #5A86AD ΔE 0.044
- Faded Blue #658CBB ΔE 0.051
- Water Blue #0E87CC ΔE 0.051
- Flat Blue #3C73A8 ΔE 0.052
Use #577CBE 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.