1、新建一个静态类ColorRevert.cs,代码如下：

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace Demo
{
    public static class ColorRevert
    {
        #region 颜色转换
        public static Color ToColor(this　string colorName)
        {
            if (colorName.StartsWith("#"))
                colorName = colorName.Replace("#", string.Empty);
            int v = int.Parse(colorName, System.Globalization.NumberStyles.HexNumber);
            return new Color()
            {
                A = Convert.ToByte((v >> 24) & 255),
                R = Convert.ToByte((v >> 16) & 255),
                G = Convert.ToByte((v >> 8) & 255),
                B = Convert.ToByte((v >> 0) & 255)
            };
        }

        public static int ToArgb(this　Color color)
        {
            int argb = color.A << 24;
            argb += color.R << 16;
            argb += color.G << 8;
            argb += color.B;
            return argb;
        }
        #endregion
    }
}

2、 新建一个Silverlight用户控件，并添加一个Rectange控件，并为其赋值填充颜色(当然这个值也可以通过数据库或参数等传递到Silverlight中并使用)

<UserControl x:Class="Demo.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    >

    <Grid x:Name="LayoutRoot" Background="White">
        <Rectangle Height="100" HorizontalAlignment="Left" Margin="306,221,0,0" Name="rectangle1" Stroke="Black" StrokeThickness="1" VerticalAlignment="Top" Width="241" />
    </Grid>
</UserControl>


using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Json;
using ESRI.ArcGIS.Client.Bing;
using ESRI.ArcGIS.Client;
using ESRI.ArcGIS.Client.Geometry;
using System.Windows.Media.Imaging;

namespace Demo
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();
            SolidColorBrush scb = new SolidColorBrush();
            scb.Color = "#FFBBCCFF".ToColor();  //核心代码在这里
            rectangle1.Fill = scb;
        }
    }
}