for anyone who finds this thread and is having the same problem. I figured it out. the color code is in status_bar_icon.xml in framework-res/res/layout: (line 5 i believe)
Code:
<TextView android:textSize="10.0sp" android:textStyle="bold" android:textColor="#ffffffff" android:gravity="center" android:layout_gravity="bottom|right|center" android:id="@id/number" android:background="@drawable/ic_notification_overlay" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginRight="1.0dip" android:layout_marginBottom="1.0dip" />
just change the android:textColor. It is in the format AARRGGBB
hope this helps.