Here`s a cool site where you can create a scrolling sign and even provides a link for you to upload your sign to imgur. It looks like you can only create a red sign but you can change the color if you have paint software of some sort.
And don`t stop there; scroll to the bottom of that page and you`ll find even more cool stuff to play with! Don`t get lost .
Signbot - Make your own animated scrolling text LED sign
Here`s a sign that I just made. I love these quickie makers!