#3F577B
Closest named color: YInMn Blue (#415A77). oklch(45.3% 0.066 258.3), rgb(63, 87, 123).
Aa
White text reads best on this color (7.34:1).
About this color
#3F577B is a medium-dark, muted blue. In OKLCH its lightness is 45%, its chroma 0.066 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is YInMn Blue (#415A77), ΔE 0.013 away. White text reads best on it, at 7.34:1.
| Hue family | Blues |
| Lightness | medium-dark (45%) |
| Chroma | muted (0.066) |
| Temperature | cool |
| Nearest name | YInMn Blue (#415A77) |
| Black text | 2.86:1 |
| White text | 7.34:1 |
Values
| HEX | #3F577B |
| RGB | rgb(63, 87, 123) |
| HSL | hsl(216, 32%, 36%) |
| OKLCH | oklch(45.3% 0.066 258.3) |
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 #3F577B | 7.34:1 | AAA | Lc -90.3 | Preferred for body text |
| Black text on #3F577B | 2.86:1 | Fails | Lc 18.6 | Dividers and decoration only |
| #3F577B text on white | 7.34:1 | AAA | Lc 85.4 | Fine for body text |
| #3F577B text on black | 2.86:1 | Fails | Lc -16.6 | Dividers and decoration only |
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 800.
-
Step 50
50
#F3F6F9
oklch(97.2% 0.005 247.9)
-
Step 100
100
#E5EAF1
oklch(93.5% 0.011 256.7)
-
Step 200
200
#D1DAE8
oklch(88.6% 0.022 259.2)
-
Step 300
300
#B2C2DA
oklch(81% 0.038 258.4)
-
Step 400
400
#89A2C8
oklch(70.7% 0.063 258.6)
-
Step 500
500
#6C8BB9
oklch(63.1% 0.078 258.1)
-
Step 600
600
#5374A6
oklch(55.5% 0.087 258.5)
-
Step 700
700
#44618E
oklch(49% 0.081 258.9)
-
Step 800
800 (this color)
#3F577B
oklch(45.3% 0.066 258.3)
-
Step 900
900
#30425D
oklch(37.6% 0.052 258.3)
-
Step 950
950
#1C2736
oklch(27% 0.032 256.3)
#3F577B 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) | #49597D | 0.016 |
| Deuteranopia (no green cones) | #42537A | 0.012 |
| Tritanopia (no blue cones) | #265F64 | 0.059 |
| Achromatopsia (no color) | #565656 | 0.066 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F577B
#3F577B
oklch(45.3% 0.066 258.3)
- #6A5229
#6A5229
oklch(45.4% 0.066 79.3)
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 #3F577B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- YInMn Blue #415A77 ΔE 0.013
- Dusk #4E5481 ΔE 0.025
- Light Navy Blue #2E5A88 ΔE 0.026
- Dusty Grape #545775 ΔE 0.030
- Denim Blue #3B5B92 ΔE 0.037
- Denim #3B638C ΔE 0.039
- Twilight #4E518B ΔE 0.041
- Dusk Blue #26538D ΔE 0.044
Use #3F577B 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.