Notifications on my Android mobile have a black and white icon at the top, but a colored icon in the message (see screenshot):
In B4A, it seems you can only do this:
B4X:
Dim n As Notification
n.Initialize
n.Vibrate=False
n.Sound=False
n.Light=False
n.Icon="icon": ' uses 72x72 icon.png (the icon assigned to the app in B4A, seems the only possibility)
n.SetInfo2("Header of the message","Message","","Main")
n.Notify(1)
I haven't done any testing but it was my understanding that the android system made the icon white when target sdk set > than a particular version. Lollipop i think...