I believe the movie was made in the 70's. (at least it was during that time I saw it). It was in color. The only part I can remember is that Earth was being invaded (of course) by telepathic (or psionic) aliens that are humanoid. I seem to remember a scene during the invasion when the (main ??) character is attacked psychically by an invader and had to break off contact because their mind was too powerful. I also seem to remember that the alien involved in the duel makes some kind of statement that it had been impressed with the human's intelligence and power. I know it's not much to go on but it was 35+ years ago.