title: Change color of inactive IconButton
body: <p>I have following widgets implemented:
  <a href="https://i.stack.imgur.com/rH2IT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rH2IT.png" alt="enter image description here" /></a></p>
  <p>Which parameter of ThemeData I should change to change grey color of IconButton?</p>
  <p>Widget code:</p>
  <pre><code>TextFormField(
                      controller: _loginPageViewModel.emailTEC,
                      validator: _loginPageViewModel.validator.validateEmail,
                      decoration: InputDecoration(
                        hintText: S.of(context).email,
                        suffixIcon: IconButton(
                          onPressed: _loginPageViewModel.emailTEC.clear,
                          icon: const Icon(Icons.clear),
                        ),
                      )
                  )
  </code></pre>
  <p>ThemeData code:</p>
  <pre><code>ThemeData(
        brightness: Brightness.light,
        //primaryColor: const Color(0xFFF8C537),
        scaffoldBackgroundColor: const Color(0xFFFFDDA1),
        appBarTheme: const AppBarTheme(
          color: Color(0xFFE53935),
        ),
        elevatedButtonTheme: ElevatedButtonThemeData(
          style: ElevatedButton.styleFrom(
              primary: const Color(0xFFFFD151),
              onPrimary: Colors.black,
              elevation: 0.5
          ),
        ),
        inputDecorationTheme: const InputDecorationTheme(
          hintStyle: TextStyle(color: Color(0xFFFFD151)),
          focusedBorder: UnderlineInputBorder(
              borderSide: BorderSide(color: Color(0xFFEDB230))
          ),
          enabledBorder: UnderlineInputBorder(
            borderSide: BorderSide(color: Color(0xFFFFD151)),
          ),
        ),
  colorScheme: ThemeData().colorScheme.copyWith(primary: Color(0xFFEDB230)),
    );
  </code></pre>