title: Flutter - Changing the border color of the OutlineInputBorder
body: <p>I'm trying to change the border color of the <code>OutlineInputBorder</code> but tried inumerous ways and failed.</p>
  
  <p>I created the whole Theme configuration through the <code>buildDarkTheme()</code> function but I can not change the border color to yellow</p>
  
  <p>Below is the image and the code:</p>
  
  <p><a href="https://i.stack.imgur.com/rpRe7.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/rpRe7.jpg" alt="enter image description here"></a></p>
  
  <pre><code>import 'package:flutter/material.dart';
  
  void main() =&gt; runApp(new MyApp());
  
  const kBlackHalf = const Color(0xFF212121);
  const kBlackLight = const Color(0xFF484848);
  const kBlack = const Color(0xFF000000);
  const kYellow = const Color(0xFFffd600);
  const kYellowLight = const Color(0xFFffff52);
  const kYellowDark = const Color(0xFFc7a500);
  const kWhite = Colors.white;
  
  ThemeData buildDarkTheme() {
    final ThemeData base = ThemeData();
    return base.copyWith(
      primaryColor: kBlack,
      accentColor: kYellow,
      scaffoldBackgroundColor: kBlackHalf,
      primaryTextTheme: buildTextTheme(base.primaryTextTheme, kWhite),
      primaryIconTheme: base.iconTheme.copyWith(color: kWhite),
      buttonColor: kYellow,
      textTheme: buildTextTheme(base.textTheme, kWhite),    
      inputDecorationTheme: InputDecorationTheme(
        border: OutlineInputBorder(
          borderSide: BorderSide(color: kYellow)
        ),
        labelStyle: TextStyle(
          color: kYellow,
          fontSize: 24.0
        ),
      ),
    );
  }
  
  TextTheme buildTextTheme(TextTheme base, Color color) {
    return base.copyWith(
      body1: base.headline.copyWith(color: color, fontSize: 16.0),
      caption: base.headline.copyWith(color: color),
      display1: base.headline.copyWith(color: color),
      button: base.headline.copyWith(color: color),
      headline: base.headline.copyWith(color: color),
      title: base.title.copyWith(color: color),
    );
  }
  
  class MyApp extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return new MaterialApp(
        theme: buildDarkTheme(),
        home: new HomePage(),
      );
    }
  }
  
  class HomePage extends StatefulWidget {
    @override
    _HomePageState createState() =&gt; new _HomePageState();
  }
  
  class _HomePageState extends State&lt;HomePage&gt; {
    String xp = '0';
  
    @override
    Widget build(BuildContext context) {
      return new Scaffold(
        appBar: new AppBar(
          actions: &lt;Widget&gt;[
            new IconButton(
              icon: Icon(Icons.ac_unit),
              onPressed: () {},
            )
          ],
        ),
        body: new Container(
          padding: new EdgeInsets.only(top: 16.0),
          child: new ListView(
            children: &lt;Widget&gt;[
              new InkWell(
                onTap: () {},
                child: new InputDecorator(
                  decoration: new InputDecoration(          
                    labelText: 'XP',
                    border: OutlineInputBorder()
                  ),
                  child: new Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    mainAxisSize: MainAxisSize.min,
                    children: &lt;Widget&gt;[
                      new Text(this.xp),
                    ],
                  ),
                ),
              )
            ],
          ),
        )
      );
    }
  }
  </code></pre>
  
  <p>For more references:</p>
  
  <p><a href="https://stackoverflow.com/questions/50122394/not-able-to-change-textfield-border-color/50351946#50351946">Not able to change TextField Border Color</a></p>
  
  <p><a href="https://github.com/flutter/flutter/issues/17592" rel="noreferrer">https://github.com/flutter/flutter/issues/17592</a></p>