#577D9B
Closest named color: Stormy Blue (#507B9C). oklch(57.3% 0.063 242.9), rgb(87, 125, 155).
Aa
Black text reads best on this color (4.81:1).
About this color
#577D9B is a medium-dark, muted blue. In OKLCH its lightness is 57%, its chroma 0.063 and its hue 243°. Its hue sits on the cool side of the wheel. The nearest named color is Stormy Blue (#507B9C), ΔE 0.011 away. Black text reads best on it, at 4.81:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | muted (0.063) |
| Temperature | cool |
| Nearest name | Stormy Blue (#507B9C) |
| Black text | 4.81:1 |
| White text | 4.36:1 |
Values
| HEX | #577D9B |
| RGB | rgb(87, 125, 155) |
| HSL | hsl(206, 28%, 47%) |
| OKLCH | oklch(57.3% 0.063 242.9) |
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 #577D9B | 4.36:1 | AA large text | Lc -75.7 | Fine for body text |
| Black text on #577D9B | 4.81:1 | AA | Lc 33.9 | Non-text elements, placeholder text |
| #577D9B text on white | 4.36:1 | AA large text | Lc 70.2 | Content text, not long reading |
| #577D9B text on black | 4.81:1 | AA | Lc -31.5 | 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
#F3F6F8
oklch(97.1% 0.004 236.5)
-
Step 100
100
#E5EBEF
oklch(93.7% 0.008 236.6)
-
Step 200
200
#D1DBE3
oklch(88.6% 0.015 241.8)
-
Step 300
300
#B2C3D2
oklch(80.9% 0.028 244.8)
-
Step 400
400
#89A4BB
oklch(70.6% 0.045 244.2)
-
Step 500
500
#6B8EAA
oklch(63.1% 0.058 242.9)
-
Step 600
600 (this color)
#577D9B
oklch(57.3% 0.063 242.9)
-
Step 700
700
#426580
oklch(49.1% 0.059 242.6)
-
Step 800
800
#375268
oklch(42.7% 0.049 243.9)
-
Step 900
900
#304454
oklch(37.7% 0.037 243.1)
-
Step 950
950
#1C2831
oklch(27% 0.024 241.1)
#577D9B 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) | #707D9C | 0.032 |
| Deuteranopia (no green cones) | #67769A | 0.026 |
| Tritanopia (no blue cones) | #3C8487 | 0.051 |
| Achromatopsia (no color) | #797979 | 0.063 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #577D9B
#577D9B
oklch(57.3% 0.063 242.9)
- #937051
#937051
oklch(57.2% 0.063 62.6)
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 #577D9B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Stormy Blue #507B9C ΔE 0.011
- Cerulean #457B9D ΔE 0.021
- Grey Blue #647D8E ΔE 0.025
- Dull Blue #49759C ΔE 0.031
- Off Blue #5684AE ΔE 0.031
- Dusty Blue #5A86AD ΔE 0.034
- Metallic Blue #4F738E ΔE 0.034
- Slate Gray #708090 ΔE 0.038
Use #577D9B 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.