Вот версия, которая поддерживает версии RGB и RGBA:
/**
* Converts a hex string to a color. If it can't be converted null is returned.
* @param hex (i.e. #CCCCCCFF or CCCCCC)
* @return Color
*/
public static Color HexToColor(String hex)
{
hex = hex.replace("#", "");
switch (hex.length()) {
case 6:
return new Color(
Integer.valueOf(hex.substring(0, 2), 16),
Integer.valueOf(hex.substring(2, 4), 16),
Integer.valueOf(hex.substring(4, 6), 16));
case 8:
return new Color(
Integer.valueOf(hex.substring(0, 2), 16),
Integer.valueOf(hex.substring(2, 4), 16),
Integer.valueOf(hex.substring(4, 6), 16),
Integer.valueOf(hex.substring(6, 8), 16));
}
return null;
}