If you are trying to access the file directly over the network in windows explorer or so you should try something like this :
\\41.xx.xx.x\Documents\logoColourBG.jpg
But if you are trying to access it from the browser your request will be handled by IIS or another web server that is installed and configured on the machine. Then you should set the folder's permissions and sharing options to default and then create a virtual directory like it is explained in here.