Wizard and the Princess

Wizard and the Princess (1980), also known as Adventure in Serenia (1982), is an adventure game by On-Line Systems for the Apple II, Atari 8-bit family, and Commodore 64. It was the second title released in On-Line Systems' Hi-Res Adventures series after Mystery House.
Wizard and the Princess is a prelude to the King's Quest series in both story and concept (though chronologically set several years before King's Quest V). It was also the first adventure game released with full color graphics.