#66739D
Closest named color: Stormy Blue (#507B9C). oklch(56.2% 0.067 270.9), rgb(102, 115, 157).
Aa
White text reads best on this color (4.66:1).
About this color
#66739D is a medium-dark, muted blue. In OKLCH its lightness is 56%, its chroma 0.067 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Stormy Blue (#507B9C), ΔE 0.034 away. White text reads best on it, at 4.66:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | muted (0.067) |
| Temperature | cool |
| Nearest name | Stormy Blue (#507B9C) |
| Black text | 4.50:1 |
| White text | 4.66:1 |
Values
| HEX | #66739D |
| RGB | rgb(102, 115, 157) |
| HSL | hsl(226, 22%, 51%) |
| OKLCH | oklch(56.2% 0.067 270.9) |
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 #66739D | 4.66:1 | AA | Lc -77.8 | Fine for body text |
| Black text on #66739D | 4.50:1 | AA | Lc 31.7 | Non-text elements, placeholder text |
| #66739D text on white | 4.66:1 | AA | Lc 72.4 | Content text, not long reading |
| #66739D text on black | 4.50:1 | AA | Lc -29.3 | 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 600.
-
Step 50
50
#F4F5F8
oklch(97% 0.004 271.4)
-
Step 100
100
#E7EAF0
oklch(93.6% 0.009 264.5)
-
Step 200
200
#D5D9E5
oklch(88.6% 0.017 271.2)
-
Step 300
300
#B9C0D5
oklch(80.9% 0.031 271)
-
Step 400
400
#95A0C0
oklch(70.8% 0.048 270.2)
-
Step 500
500
#7B88B0
oklch(63.1% 0.062 270.6)
-
Step 600
600 (this color)
#66739D
oklch(56.2% 0.067 270.9)
-
Step 700
700
#535F85
oklch(49.1% 0.063 270.5)
-
Step 800
800
#444E6C
oklch(42.8% 0.052 269.9)
-
Step 900
900
#394157
oklch(37.7% 0.039 269)
-
Step 950
950
#222633
oklch(27.1% 0.025 271.4)
#66739D 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) | #66779F | 0.011 |
| Deuteranopia (no green cones) | #61729C | 0.008 |
| Tritanopia (no blue cones) | #567B82 | 0.059 |
| Achromatopsia (no color) | #747474 | 0.067 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66739D
#66739D
oklch(56.2% 0.067 270.9)
- #847445
#847445
oklch(56.3% 0.068 91.3)
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 #66739D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Stormy Blue #507B9C ΔE 0.034
- Dull Blue #49759C ΔE 0.036
- Metallic Blue #4F738E ΔE 0.040
- Cerulean #457B9D ΔE 0.042
- Grey Blue #647D8E ΔE 0.043
- Grey Purple #826D8C ΔE 0.047
- Off Blue #5684AE ΔE 0.049
- Flat Blue #3C73A8 ΔE 0.050
Use #66739D 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.