How to change textField underline color?

Just used -:

decoration: InputDecoration(        
              enabledBorder: UnderlineInputBorder(      
                      borderSide: BorderSide(color: Colors.cyan),   
                      ),  
              focusedBorder: UnderlineInputBorder(
                      borderSide: BorderSide(color: Colors.cyan),
                   ),  
             ),

it works for me 🙂