wpf - change the color of the png image using expression blend -

there might duplicates of question didnt find exact solution problem.

i have image. source of image png image named add.png. shape of add.png plus(+) symbol. color white @ moment.

i want change white color green when mouse cursor goes on it. property of image should change change color.

i don't want change source of image.

edit :

why don't want change image source :

basically have rectangle , keep image on it. on mouseover , mouseleave change fill color of rectangle using changepropertyaction. when click on image want change source.

but when program runs error sayin windows explorer has stopped working. when see output window errors system.nullreferenceexception: object reference not set instance of object

it easier. change image source. options limited here: create own effect derive system.windows.media.effects.effect, call coloreffect , implement color change logic there, similar alternative create separate pixelshader effect more complex effect above. use image processing http://www.codeproject.com/articles/237226/image-processing-is-done-using-wpf