title: Hex colors in Android are sometimes eight digits. How? What is the difference between #FFFFFF and #FFFFFF00?
body: <p>I sometimes have seen in examples where the coloring in Android is done as #FF191919. I mean an eight-digit hex number. But it should only be a six-digit number. How are they related?</p>
  <p>If I want to convert a six-digit number to a eight-digit number, how can I do it? I mean convert #424242 to a eight-digit number coloring? What are the the details?</p>