When you create a shape in Lectora, you can choose to fill the shape with either a solid color, or a completely transparent fill. I would like the ability to fill a shape with a color, and then choose a transparency level for the color. That way you can create a highlight box for overlaying both text and pictures. I'm working around it now by creating a text box with a transparent background, and making a colored shape appear behind the text I want to highlight. But I can't figure out a way to make a semi-transparent shape overlay a picture, allowing me to highlight objects within an image.
