In Project View, select your object to highlight it.
In the Object Property menu under Appearance, change the color of the selected object. A preview of each color is displayed beside each color name.
For no color/transparent colors (invisible), choose Transparent Black.
If the entire object is Transparent Black, the object is "invisible" (cannot be seen) but still exists on the work area. Click and drag a selection box in the work area to see where the object is located.
Transparent objects can be used to overlay on top of other buttons.