using System.Windows.Media;

//String转换成Color

Color color = (Color)ColorConverter.ConvertFromString(string);

//String转换成Brush

BrushConverter brushConverter = new BrushConverter();

Brush brush = (Brush)brushConverter.ConvertFromString(string);

//Color转换成Brush

Brush brush = new SolidColorBrush(color));

//Brush转换成Color有两种方法：

//先将Brush转成string，再转成Color。

Color color= (Color)ColorConverter.ConvertFromString(brush.ToString());

//将Brush转成SolidColorBrush，再取Color。

Color color= ((SolidColorBrush)CadColor.Background).Color;