Sorry, I have to re-open this previous thread as I am no longer able to add something there:
The answer from Chelsea does not help. After I have set the style effects for the first time I see the entries in the New Interaction list, but all are disabled:
Still I am unable to change the style effects for a check box after it as been set once.
Hi yaba,
Oh I think I see what you mean! My apologies for the confusion—once you’ve added those style effects to your widget, you might need to click on their respective styling areas shown near the top of the Interactions pane to modify them:
Once you’ve clicked on one of these style effects, click the checkboxes where you need to apply style changes. For example, if you only need to change the fill color, you can check the “Fill Color” box, then click the color picking field to choose the new fill color.
We also offer an article on style effects on our site here.
I hope that helps!
Oh, yes that works. Thank you!.. and I frequently clicked there and nothing happened. Just saw that you need to click on the text to make it expand and clicking on the row does not work. 
Also is there any reason why every element has “Style Effects” in its context menu, but a check box does not?
There are quite some Usability issues in Axure 9 
