改变Error tip的背景色.

通过设置 .errorTip CSS选择器的 borderColor 样式。
示例：

代码：

<? xml version="1.0" encoding="utf-8" ?>
<!--  http://blog.flexexamples.com/2008/05/22/changing-the-background-color-of-an-error-tip-in-flex/  -->
< mx:Application  xmlns:mx ="http://www.adobe.com/2006/mxml"
        layout ="vertical"
        verticalAlign ="middle"
        backgroundColor ="white" >

     < mx:Style >
        @font-face {
            src: local("Base 02");
            fontFamily: Base02Embedded;
        }

        .errorTip {
            borderColor: haloOrange;
            color: black;
            fontFamily: Base02Embedded;
            fontSize: 16;
            fontWeight: normal;
        }

        TextInput {
            errorColor: haloOrange;
        }
     </ mx:Style >

     < mx:TextInput  id ="textInput"
            errorString ="Hey, you missed a spot!"   />

</ mx:Application >

来自： http://blog.flexexamples.com/2008/05/22/changing-the-background-color-of-an-error-tip-in-flex/