#66739B
Closest named color: Stormy Blue (#507B9C). oklch(56.1% 0.064 270.3), rgb(102, 115, 155).
Aa
White text reads best on this color (4.67:1).
About this color
#66739B is a medium-dark, muted blue. In OKLCH its lightness is 56%, its chroma 0.064 and its hue 270°. Its hue sits on the cool side of the wheel. The nearest named color is Stormy Blue (#507B9C), ΔE 0.033 away. White text reads best on it, at 4.67:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | muted (0.064) |
| Temperature | cool |
| Nearest name | Stormy Blue (#507B9C) |
| Black text | 4.49:1 |
| White text | 4.67:1 |
Values
| HEX | #66739B |
| RGB | rgb(102, 115, 155) |
| HSL | hsl(225, 21%, 50%) |
| OKLCH | oklch(56.1% 0.064 270.3) |
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 #66739B | 4.67:1 | AA | Lc -77.9 | Fine for body text |
| Black text on #66739B | 4.49:1 | AA large text | Lc 31.6 | Non-text elements, placeholder text |
| #66739B text on white | 4.67:1 | AA | Lc 72.5 | Content text, not long reading |
| #66739B text on black | 4.49:1 | AA large text | Lc -29.2 | 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
#D5D9E4
oklch(88.5% 0.016 270)
-
Step 300
300
#B9C0D4
oklch(80.9% 0.029 270.3)
-
Step 400
400
#95A0BE
oklch(70.7% 0.046 269.4)
-
Step 500
500
#7C88AE
oklch(63.1% 0.059 271)
-
Step 600
600 (this color)
#66739B
oklch(56.1% 0.064 270.3)
-
Step 700
700
#545F83
oklch(49.1% 0.06 271)
-
Step 800
800
#444E6B
oklch(42.7% 0.05 269.5)
-
Step 900
900
#3A4156
oklch(37.8% 0.037 270.2)
-
Step 950
950
#222633
oklch(27.1% 0.025 271.4)
#66739B 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) | #66769D | 0.008 |
| Deuteranopia (no green cones) | #62729A | 0.007 |
| Tritanopia (no blue cones) | #577B81 | 0.058 |
| Achromatopsia (no color) | #747474 | 0.064 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66739B
#66739B
oklch(56.1% 0.064 270.3)
- #837348
#837348
oklch(56% 0.063 89.8)
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 #66739B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Stormy Blue #507B9C ΔE 0.033
- Dull Blue #49759C ΔE 0.035
- Metallic Blue #4F738E ΔE 0.038
- Grey Blue #647D8E ΔE 0.041
- Cerulean #457B9D ΔE 0.042
- Grey Purple #826D8C ΔE 0.046
- Slate Gray #708090 ΔE 0.049
- Battleship Gray #6C757D ΔE 0.050
Use #66739B 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.