Captivate 9 - Hightlightbox properties > Fill and Stroke greyed out

Maybe it is my eyes, but to me both Fill and Stroke look active, not greyed out.

What is greyed out is the choice for Fill: which means you cannot use a texture, nor a gradient, nor an image for the Fill; it has to be always a solid color. But you can choose the color, alpha and indicate if you want the outer area to be filled instead of the inner area.

Bit similar for the Stroke: what is dimmed is the kind of stroke, because dashed stroke is not allowed for a highlight box. But you can choose the color and the stroke width.

Look also in the Object Style Manager, if you want to change the colors, alpha permanently.