Traveling by truck on Rte 105 East from Derby to East Charleston. Observed a bright orange light traveling slowly (est. 80-100mph)from southeast to northwest. It was full darkness and sky was overcast(approx 500ft) and object was below clouds. Object size estimated 40 to 50 feet with no discernible outlines. No anti-collision, landing or strobe lights noted. I stopped my truck in the parking lot of an abandoned gas station to watch the object. There was no sound coming from it as it passed overhead. The object faded rapidly into the overcast, apparently accelerating upward at an angle.Note: The US Border Patrol sometimes flies fairly large drones along the nearby Canadian border and I have seen these several times. This object was not a drone. The light coming from the object was a steady, brilliant orange (not red) and very unusual. The weather conditions were not conducive to small aircraft and this object did not display proper FAA lighting.