title: Change Android small notification icon color depending on context
body: <p>I've been scouring stack overflow for days to find the answer to this question, but I cannot figure it out for the life of me :-/</p>
  
  <p>On my Samsung S6 with Android O, apps like Gmail have white notifications for the status bar but red/blue/green/whatever notifications when you pull the notifications down to inspect them individually.  See for example the attached photos - Gmail red when the notifications are displayed and white in the notification bar.</p>
  
  <p>What type of programatic Android sorcery must one do to accomplish this? More specifically, in Notification.Builder, what values do I need to set to get it to display this way?  Are there two different icons?  Is there one drawable with multiple layers?  If so, how does one choose which layers are shown where?  Thanks!</p>
  
  <p><a href="https://i.stack.imgur.com/Tge6W.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Tge6W.png" alt="beautiful red color for gmail"></a>
  <a href="https://i.stack.imgur.com/UEmPj.png" rel="noreferrer"><img src="https://i.stack.imgur.com/UEmPj.png" alt="stark white color for gmail"></a></p>