在鼠标悬停XAML wpf上将按钮默认突出显示的颜色更改为透明？

I have a button with transparent background. When i move mouse over on the button, a light blue colour appears on the button(Default Colour) obviously. what i want is that my button background should remain transparent even when the mouse is over the button. How can i do it in XAML? i have searched it but couldn't find anything related to my problem. Almost Every Example or walkthrough is for changing styles and templates of the button.I have a button with transparent background. Wh