#577FB1
Closest named color: Off Blue (#5684AE). oklch(58.8% 0.089 254.5), rgb(87, 127, 177).
Aa
Black text reads best on this color (5.07:1).
About this color
#577FB1 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.089 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Off Blue (#5684AE), ΔE 0.016 away. Black text reads best on it, at 5.07:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.089) |
| Temperature | cool |
| Nearest name | Off Blue (#5684AE) |
| Black text | 5.07:1 |
| White text | 4.13:1 |
Values
| HEX | #577FB1 |
| RGB | rgb(87, 127, 177) |
| HSL | hsl(213, 37%, 52%) |
| OKLCH | oklch(58.8% 0.089 254.5) |
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 #577FB1 | 4.13:1 | AA large text | Lc -73.9 | Content text, not long reading |
| Black text on #577FB1 | 5.07:1 | AA | Lc 35.7 | Non-text elements, placeholder text |
| #577FB1 text on white | 4.13:1 | AA large text | Lc 68.4 | Content text, not long reading |
| #577FB1 text on black | 5.07:1 | 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
#F3F6F9
oklch(97.2% 0.005 247.9)
-
Step 100
100
#E5EAF2
oklch(93.6% 0.012 259.8)
-
Step 200
200
#CFDAE8
oklch(88.4% 0.023 254.4)
-
Step 300
300
#AFC2DB
oklch(80.8% 0.041 255.3)
-
Step 400
400
#85A3C9
oklch(70.7% 0.065 254.6)
-
Step 500
500
#678CBB
oklch(63.1% 0.083 254.8)
-
Step 600
600 (this color)
#577FB1
oklch(58.8% 0.089 254.5)
-
Step 700
700
#3F628F
oklch(49% 0.083 255.2)
-
Step 800
800
#345074
oklch(42.6% 0.069 255.2)
-
Step 900
900
#2D435E
oklch(37.7% 0.054 254.1)
-
Step 950
950
#1B2737
oklch(26.9% 0.034 255.8)
#577FB1 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) | #6B82B3 | 0.027 |
| Deuteranopia (no green cones) | #6079B0 | 0.018 |
| Tritanopia (no blue cones) | #2C8A90 | 0.079 |
| Achromatopsia (no color) | #7D7D7D | 0.089 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #577FB1
#577FB1
oklch(58.8% 0.089 254.5)
- #9C753C
#9C753C
oklch(58.9% 0.089 74.9)
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 #577FB1, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Off Blue #5684AE ΔE 0.016
- Steel Blue #4682B4 ΔE 0.018
- Cool Blue #4984B8 ΔE 0.019
- Dusty Blue #5A86AD ΔE 0.023
- Stormy Blue #507B9C ΔE 0.034
- Cerulean #457B9D ΔE 0.039
- Faded Blue #658CBB ΔE 0.042
- Dull Blue #49759C ΔE 0.044
Use #577FB1 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.