Setting EditText underline color in Android

For API 21 (Lollipop) and above, just set the color of property backgroundTint on the EditText

For Pre Lollipop, API 21 and below.

The quick and easy way.

The more complex way but with more control and customization if needed.

text_box_underline.xml

text_box_underline_activated.xml

text_box_underline_selector.xml

Assign the selector to the background of the EditText.

References:
http://stackoverflow.com/questions/14542557/android-different-edittext-backgrounds-for-different-states-using-shapes-select
http://stackoverflow.com/questions/26574328/changing-edittext-bottom-line-color-with-appcompat-v7
http://stackoverflow.com/questions/24677414/how-to-change-line-color-in-edittext