Вы можете попробовать что-то вроде:
var colorTransform:ColorTransform = linkbar.transform.colorTransform;
colorTransform.color = 0x009900;
linkbar.transform.colorTransform = colorTransform;
linkbar.alpha = .2
Или создать пользовательскую кнопку, как это:
LinkButton
{
textRollOverColor: #006699;
textSelectedColor: #003366;
/* Yes, this one controls the selected button's text color */
disabledColor: #0099cc;
/*Use DownSkin for Disabled to simulate Active/Selected Button */
disabledSkin: Embed(source="theme1.swf", symbol="LinkButton_downSkin");
downSkin: Embed(source="theme1.swf", symbol="LinkButton_downSkin");
overSkin: Embed(source="theme1.swf", symbol="LinkButton_overSkin");
upSkin: Embed(source="theme1.swf", symbol="LinkButton_upSkin");
font-size: 14;
font-weight: bold;
}