Describe the solution you'd like
A way to easily create certain skeleton animations.
now:

Skeleton(
  width: 200,
  height: 14,
  radius: Radius.circular(6),
)

With 'styles':

Skeleton(
  style: SkeletonStyle.text
)

I try to add border with container but doesn't worked too. How can i add border to skeleton ?

Describe the bug
The skeleton animation won't show the correct color if the background color isn't white or dark grey.

To Reproduce
Create a container with any color background (like green) and place a skeleton animation inside.

Container(
  height: 60,
  color: Colors.green,
  padding: EdgeInsets.symmetric(horizontal: 16, vertical: 22),
  child: Skeleton(
    height: 16,
    style: SkeletonStyle.text,
  ),
);

Desktop (please complete the following information):

• OS: Windows 10 x64
• Flutter version 1.22.3
• Version 0.0.3