Here we have a System SVG icons that you can be integrated in your own graphics designs. And among other things, this flat design is pretty important for your work.
You have the download buttons bellow and can choose between two popular extensions, SVG or PNG formats. Also, before downloading the System SVG icon, you can try the colors from the top of the icon, and test it, if the color fit with your ideas. If not, just refresh the page and you'll have new posibillities