The one i saw around a couple decades ago was triangular shaped and pulsating multicolored, but it was no 17 inch mylar balloon.
On an evening with no wind, it flew straight as an arrow, faster than a jet (without a sound), and was longer and wider than my house (flew right over it).
I saw a silent daytime disc traveling rapidly against the prevailing wind on one occasion, and on another a year later, a nighttime silent craft/structured circular object that rose up from the valley, flew over my head, changed color and shot off. I estimated it to be about 200 feet up at that point and 20 feet in circumference based on how big a car seen in the valley would be from that perspective. No idea what either was.