It's my first time using XF, and I've sorted most of the stuff. I've installed a style, but I'm looking to alter the node icon that shows if it has unread/new posts in it. Currently, it's a white envelope when there aren't any new posts, and it changes to a blue colour when there are new ones. I need this to be an orange colour, but I can't for the life of me find the image or where to upload one. Is this not done through uploading an image?