title: Change React-Native TextInput's placeholder color
body: <p>I'm creating an Android app using React Native in which there's a form. The placeholder doesn't even appear for the textInput fields so I thought of changing the placeholder color but I don't know how to do that. The docs mentioned some way which I don't understand.</p>
  
  <p>Here's the code:</p>
  
  <pre><code>  &lt;TextInput
    secureTextEntry={secureTextEntry}
    style={inputStyle}
    placeholder={placeholder}
    value={value}
    onChangeText={onChangeText}
    /&gt;
  
    inputStyle: {
    color: '#000',
    paddingRight: 5,
    paddingLeft: 5,
    fontSize: 18,
    lineHeight: 23,
    flex: 2,
    }
  </code></pre>
  
  <p>I also tried: </p>
  
  <pre><code>  &lt;TextInput
    placeholderTextColor="blue"
    style={inputStyle}
    placeholder={placeholder}
    value={value}
    onChangeText={onChangeText}
    /&gt;
  </code></pre>
  
  <p>and </p>
  
  <pre><code>  inputStyle: {
    color: '#000',
    paddingRight: 5,
    paddingLeft: 5,
    fontSize: 18,
    lineHeight: 23,
    flex: 2,
    placeholderTextColor: '#333'
    }
  </code></pre>