[안드로이드 스튜디오] toast 메세지 배경색 바꾸는 방법

http://heum-story.tistory.com/20

https://stackoverflow.com/questions/31175601/how-can-i-change-default-toast-message-color-and-background-color-in-android

https://m.blog.naver.com/PostView.nhn?blogId=dla210&logNo=220708153806&proxyReferer=https%3A%2F%2Fwww.google.com%2F