Answers for "how to set error in textfield in flutter"

text fieldform color flutter

TextField(
  style: TextStyle(color: Colors.red),
  decoration: InputDecoration(fillColor: Colors.orange, filled: true),
)

textfield set value flutter

/// You can use a [TextFormField] instead of [TextField]
/// and use the [initialValue] property. for example:

TextFormField(initialValue: "I am smart")