If you are looking for flat design, this T-shirt Outline svg icon might be perfect for you. It's free and like all the other SVG icons, this one looks great too.
You have the download buttons bellow and can choose between two popular extensions, SVG or PNG formats. Also, before downloading the T shirt Outline 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