Orange lights mean there is a possible display output problem. Try these steps:
Disconnect the cable between your Xbox and the TV (both ends) and plug it all back in again. See if it works.
Try a different cable if you can to see if the cable itself is at fault.
As it works for a while it cold either be movement around the console/TV that works the connection loose or it could be that the GFX is overheating and the console isn't getting enough air circulating around it (make sure it has lots of room and that the vents on the console are clear of any dust) or is slowly giving up which would require repair/replacement of the console.