title: How to change colour of the thumb in seekbar?
body: <p>I have the default <code>seekbar</code> in my android app. I noticed that when the <code>thumb</code> on the <code>seekbar</code> is held, it turns yellow. Instead, I want it to turn blue when it is held. How can this be done? I apologize if this is a basic question, I am new to android development. Thanks.</p>