Android App Button background Color Issue

Hi frnd…

I have installed the new Android App version 4.1. Now when I chose the button it shows the blue background and when I have changed it through the code, it is not changing.
What is the issue have in it. Please tell me how to resolve this issue.

Hello bro, the blue color is not the background color and if you run the app you will not see it on the device, this only from Android Studio IDE to highlight the selected view which is your ConstraintLayout