public borderColor : Number
The color of the text field border. The default is 0x000000 (black). This property may be retrieved or set, even if there is currently no border.
The following example creates a text field called my_txt, sets the border property to true, and displays some text in the field.
this.createTextField("my_txt", this.getNextHighestDepth(), 10, 10, 320, 240);
my_txt.border = true;
my_txt.borderColor = 0x00FF00;
my_txt.text = "Lorum ipsum";