Bubble Background Color Once Activated

i hope this is my last question, lol. love the support by the way!
i have my site locked in just the way i want and not to sound picky but is there a way to change the bubble color once you “hover” over it and attempt to activate the post? i know how to change the bubble color to show up solid but i do not know how to change in when you hover over it. if you view my site currently and hover over the bubble it will show a “gray” bubble and i want to make that white but only when its hovered over. i have the css manager installed.

spicelean.com