如何用代码改变进度条的颜色？

我在应用程序中设置一个水平的进度条，现在想改变这个进度条的颜色，我不用XML,用代码如何实现呢？

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">

<item android:id="@android:id/background">
    <shape>
        <corners android:radius="5dip" />
        <gradient
                android:startColor="#ff9d9e9d"
                android:centerColor="#ff5a5d5a"
                android:centerY="0.75"
                android:endColor="#ff747674"
                android:angle="270"
        />
    </shape>
</item>

<item android:id="@android:id/secondaryProgress">
    <clip>
        <shape>
            <corners android:radius="5dip" />
            <gradient
                    android:startColor="#80ffd300"
                    android:centerColor="#80ffb600"
                    android:centerY="0.75"
                    android:endColor="#a0ffcb00"
                    android:angle="270"
            />
        </shape>
    </clip>
</item>
<item
    android:id="@android:id/progress"
>
    <clip>
        <shape>
            <corners
                android:radius="5dip" />
            <gradient
                android:startColor="@color/progress_start"
                android:endColor="@color/progress_end"
                android:angle="270" />
        </shape>
    </clip>
</item>

</layer-list>

我之前遇到的这个问题是用下面这个代码解决的。

progressDialog.setMessage(
    Html.fromHtml("<font color='white'>" + Message + "</font>"));

<SeekBar
        android:id="@+id/seekBar"
        style="@android:style/Widget.ProgressBar.Horizontal"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:maxHeight="8dp"
        android:minHeight="8dp"
        android:progressDrawable="@drawable/your_style"
        android:thumb="@drawable/your_style" />
ProgressDialog pd=new ProgressDialog(this);
pd.setProgressDrawable(getResources().getDrawable(id));

<item name="android:indeterminateOnly">true</item> <item name="android:indeterminateDrawable">@android:drawable/progress_medium_white</item> <item name="android:indeterminateBehavior">repeat</item> <item name="android:indeterminateDuration">3500</item> <item name="android:minWidth">48dip</item> <item name="android:maxWidth">48dip</item> <item name="android:minHeight">48dip</item> <item name="android:maxHeight">48dip</item> <item name="android:indeterminateOnly">true</item> <item name="android:indeterminateDrawable">@android:drawable/progress_medium_white</item> <item name="android:indeterminateBehavior">repeat</item> <item name="android:indeterminateDuration">3500</item> <item name="android:minWidth">48dip</item> <item name="android:maxWidth">48dip</item> <item name="android:minHeight">48dip</item> <item name="android:maxHeight">48dip</item>

bootStrap技术...........................