Custom component implementations using Material elements often want to apply theme colors to their custom components. Consider the custom `<user-card>` component below where the `md-colors` attribute is used to color the background and text colors using either the current or specified theme palette colors.

#### `<user-card>` without md-color features

#### `<user-card>` coloring using the 'default' theme

#### `<user-card>` coloring using the 'forest' theme

Note: The `md-colors` directive allows pre-defined theme colors to be applied as CSS style properties. `md-colors` uses the palettes defined in the Material Design Colors and the themes defined using `$mdThemingProvider`. This directive is an extension of the `$mdTheming` features.