#3F688B
Closest named color: Denim (#3B638C). oklch(50.2% 0.073 245.7), rgb(63, 104, 139).
Aa
White text reads best on this color (5.89:1).
About this color
#3F688B is a medium-dark, moderately saturated blue. In OKLCH its lightness is 50%, its chroma 0.073 and its hue 246°. Its hue sits on the cool side of the wheel. The nearest named color is Denim (#3B638C), ΔE 0.017 away. White text reads best on it, at 5.89:1.
| Hue family | Blues |
| Lightness | medium-dark (50%) |
| Chroma | moderately saturated (0.073) |
| Temperature | cool |
| Nearest name | Denim (#3B638C) |
| Black text | 3.56:1 |
| White text | 5.89:1 |
Values
| HEX | #3F688B |
| RGB | rgb(63, 104, 139) |
| HSL | hsl(208, 38%, 40%) |
| OKLCH | oklch(50.2% 0.073 245.7) |
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 #3F688B | 5.89:1 | AA | Lc -84.6 | Fine for body text |
| Black text on #3F688B | 3.56:1 | AA large text | Lc 24.7 | Dividers and decoration only |
| #3F688B text on white | 5.89:1 | AA | Lc 79.4 | Fine for body text |
| #3F688B text on black | 3.56:1 | AA large text | Lc -22.5 | 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 700.
-
Step 50
50
#F3F6F8
oklch(97.1% 0.004 236.5)
-
Step 100
100
#E4EBF0
oklch(93.6% 0.01 238.5)
-
Step 200
200
#CFDBE6
oklch(88.6% 0.02 245.7)
-
Step 300
300
#AFC3D6
oklch(80.8% 0.035 246.9)
-
Step 400
400
#84A5C2
oklch(70.8% 0.056 245.2)
-
Step 500
500
#648EB3
oklch(63.1% 0.073 245.9)
-
Step 600
600
#4B789E
oklch(55.6% 0.077 245.3)
-
Step 700
700 (this color)
#3F688B
oklch(50.2% 0.073 245.7)
-
Step 800
800
#32526E
oklch(42.6% 0.06 246.2)
-
Step 900
900
#2C4459
oklch(37.6% 0.047 245.9)
-
Step 950
950
#1A2834
oklch(27% 0.03 245.1)
#3F688B 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) | #59698D | 0.033 |
| Deuteranopia (no green cones) | #4F618A | 0.026 |
| Tritanopia (no blue cones) | #117074 | 0.061 |
| Achromatopsia (no color) | #646464 | 0.073 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F688B
#3F688B
oklch(50.2% 0.073 245.7)
- #805B35
#805B35
oklch(50.2% 0.072 65.6)
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 #3F688B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Denim #3B638C ΔE 0.017
- Dusky Blue #475F94 ΔE 0.034
- Muted Blue #3B719F ΔE 0.036
- Metallic Blue #4F738E ΔE 0.040
- Peacock Blue #016795 ΔE 0.040
- Ocean Blue #03719C ΔE 0.042
- Slate #516572 ΔE 0.042
- Sea Blue #047495 ΔE 0.043
Use #3F688B 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.