[FMX] Adding a gradient problem

Hi. I’ve made a movie in which you can drag duplicate clips and drop them on a shape to change the colour of the shape movieclip. It all works fine apart from I need a translucent gradient over the shape so that when the colour is changed it always has the feel of being a sphere rather than a flat circle. However, when I put the gradient graphic (with a low alpha value) on a higher layer than the shape movieclip, it “blocks” the draggable clips from being able to change the colour of the shape clip. Does anyone know of any ways to get round this problem, please?
Cheers,
Dave