Another possibility might be Jon van Canegham's original King's Bounty (New World Computing, 1990. But I don't remember there being buttons in a circle. Side note: the first Heroes of Might & Magic was based on KB.)

There was another game, an American spin-off of Germany's (translating from German,) The Dark Eye. I believe it had the circle and the colored buttons. Darn! I forget what it was called. (I turned 78 last month.) Some years later, another U.S. game was actually called The Dark Eye, but apparently wasn't related. I played the first game a lot, but never finished it. In those days, there was no internet, and if it wasn't in a fanzine's Q & E column or a Shay Addams hint book, you were outta luck for getting past really difficult puzzles in games. (In those days there were very, very few Prima or Bradygames hint books.) I wish I could remember its name, because I really think this may have been the game you seek. I remember you had to choose your party from choices indicated by red, yellow, green, and blue buttons