#3F667B
Closest named color: Slate (#516572). oklch(49% 0.056 233.1), rgb(63, 102, 123).
Aa
White text reads best on this color (6.18:1).
About this color
#3F667B is a medium-dark, muted blue. In OKLCH its lightness is 49%, its chroma 0.056 and its hue 233°. Its hue sits on the cool side of the wheel. The nearest named color is Slate (#516572), ΔE 0.024 away. White text reads best on it, at 6.18:1.
| Hue family | Blues |
| Lightness | medium-dark (49%) |
| Chroma | muted (0.056) |
| Temperature | cool |
| Nearest name | Slate (#516572) |
| Black text | 3.39:1 |
| White text | 6.18:1 |
Values
| HEX | #3F667B |
| RGB | rgb(63, 102, 123) |
| HSL | hsl(201, 32%, 36%) |
| OKLCH | oklch(49% 0.056 233.1) |
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 #3F667B | 6.18:1 | AA | Lc -85.9 | Fine for body text |
| Black text on #3F667B | 3.39:1 | AA large text | Lc 23.3 | Dividers and decoration only |
| #3F667B text on white | 6.18:1 | AA | Lc 80.7 | Fine for body text |
| #3F667B text on black | 3.39:1 | AA large text | Lc -21.1 | 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
#F3F6F7
oklch(97.1% 0.003 219.5)
-
Step 100
100
#E5EBEE
oklch(93.6% 0.008 228.9)
-
Step 200
200
#D0DBE1
oklch(88.5% 0.015 231.2)
-
Step 300
300
#B0C4CF
oklch(80.9% 0.027 231.7)
-
Step 400
400
#87A6B7
oklch(70.8% 0.042 232.1)
-
Step 500
500
#6890A6
oklch(63.2% 0.055 232.8)
-
Step 600
600
#4F7A91
oklch(55.7% 0.059 232.7)
-
Step 700
700 (this color)
#3F667B
oklch(49% 0.056 233.1)
-
Step 800
800
#355364
oklch(42.6% 0.045 234.2)
-
Step 900
900
#2E4552
oklch(37.7% 0.036 233.8)
-
Step 950
950
#1B2830
oklch(26.9% 0.023 235.8)
#3F667B 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) | #5C657C | 0.037 |
| Deuteranopia (no green cones) | #535E7B | 0.033 |
| Tritanopia (no blue cones) | #236C6D | 0.042 |
| Achromatopsia (no color) | #616161 | 0.056 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F667B
#3F667B
oklch(49% 0.056 233.1)
- #7A5843
#7A5843
oklch(49.1% 0.055 52.7)
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 #3F667B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Slate #516572 ΔE 0.024
- Denim #3B638C ΔE 0.032
- YInMn Blue #415A77 ΔE 0.036
- Dusty Grape #545775 ΔE 0.048
- Metallic Blue #4F738E ΔE 0.050
- Dark Aqua #05696B ΔE 0.050
- Light Navy Blue #2E5A88 ΔE 0.052
- Dusky Blue #475F94 ΔE 0.052
Use #3F667B 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.