Creating an android notification icon


Please I have developed my mobile app that has local notification enabled, but the problem I have is, the notification icon showing on the notification panel is not like others, the background color I used doesn’t cover every part of the notification icon when displayed in android notification panel, I have seen other apps and how their notification icon color covers every where, how can I achieve this. Pls check the uploaded image so you can get what am trying to say. My app is the one with orange logo while the other is for another, I want to achieve something like the one in blue.