Like this? http://i.imgur.com/iOb3lPG.png
I did this in about 2 minutes with GIMP
If you want to edit images I would highly recommend GIMP, at least as side programs, it can be pretty confusing but I use it fairly often and it isn't bad. Compared to photoshop I think photoshop would be better however gimp can do quite a lot, definitely all that I need it to do, but yeah, the biggest thing is it being confusing to learn at the start.
If you want to know how I did it I opened the image with GIMP, pressed control + A to select the entire image, when to Color> Color to Alpha, and pressed ok on the window that popped up. Keep in mind this only works for white defaulty, if you want to do another color simply click on the color box when the window comes up and select your color, there is also a color picker.
Hope this helped c:
EDIT: I just realized if you open the image it appears no different but if you drag it onto your desktop it will be transparent and not white ;)
Edited by Unicycle43, 10 September 2016 - 08:20 PM.