@ Konrad Krakowiak прав. Вы можете увидеть исходный код android.app.ActivityManager # TaskDescription.
/**
* Creates the TaskDescription to the specified values.
*
* @param label A label and description of the current state of this task.
* @param icon An icon that represents the current state of this task.
* @param colorPrimary A color to override the theme's primary color. This color must be opaque.
*/
public TaskDescription(String label, Bitmap icon, int colorPrimary) {
if ((colorPrimary != 0) && (Color.alpha(colorPrimary) != 255)) {
throw new RuntimeException("A TaskDescription's primary color should be opaque");
}
mLabel = label;
mIcon = icon;
mColorPrimary = colorPrimary;
}