Stefania D'Alessandro/Getty Images

Can a dress really make a woman look sizes slimmer?

Designer Stella McCartney’s dress, the Bicolour Octavia, is turning heads for doing just that.

The fitted garment owes its slimming effect to clever color-blocking – panels of contoured, colored stretch fabric in the front and back, and stretchy black panels at the sides. The black panels are barely visible, which forces the eye to focus only on the contrasting panels – giving the wearer the illusion of having a more slender, yet more curvy figure.

“It’s like retouching your body with a frock,” celebrity stylist June Ambrose told the New York Post.

Hollywood’s A-listers are fans, and the Bicolour Octavia is being dubbed the “miracle dress.”

Actress Kate Winslet turned heads at the 68 th Venice Film Festival earlier this month when she stepped out on the red carpet in a fitted black and white Bicolour Octavia. Singer and “X-Factor” host Nicole Scherzinger, actress Liv Tyler, singer Gloria Estefan and TV personality La La Anthony have all worn the dress to rave reviews.

The dress is from McCartney’s Winter 2011 collection.  Fans of the version of the dress worn by Liv Tyler will have to wait.  That style will not be in stores until mid-November, in the Spring 2012 line.

Knockoffs of the dress are already available. The Post says UK-based retailer Topshop — favorite of Kate Middleton – offers a chocolate and cappuccino dress for $84.

Bebe offers its own $69 version, complete with “body-embracing stretch.”

But even though a McCartney original retails for $1,595, the high price doesn’t seem to have affected sales. A check of the designer’s website tonight revealed the style is out of stock.