The Encyclopedia of Walt Disney's Animated Characters: From Mickey Mouse to Hercules by
John Grant

Walt Disney Character Description of The Prince from "Snow White and the Seven Dwarfs" (1937)

If Snow White is, as it were, a "strong cypher", the Prince is a weak one. For an important central character he appears on the screen for an astonishingly short period of time - once early on when singing "One Song" with Snow White and the other time right at the end when his kiss wakes her from her otherwise endless sleep. Strangely enough, although he has only a few lines, his voice part proved the most difficult in the film to cast aside from that of Snow White, and indeed it was the last one to be finalized, the part eventually going to the established actor Harry Stockwell. The problem was that of finding a voice that captured the Prince's screen image as a robust, handsome young man (he had originally been envisaged as a Douglas Fairbanks type). In the event Stockwell achieved this to perfection.
We first see the Prince riding along on his pure-white steed outside the castle walls and hearing Snow White singing beguilingly. It is the work of a moment for him to shin over the wall and join her. His masculinity is impressive and yet not overcrowding; it contrasts interestingly with Snow White's much more youthful femininity - in terms of appearance he is at least ten years her senior. Like her he is depicted in "earth" colours: tall and slender, he has brown hair and his clothing is brown, white and clear blue. He shares with her the dramatic piece of animation when he joins her at the end of "I'm Wishing" while we see their faces reflected in the waters of the wishing-well.
Walt was obviously very sensitive to the criticism that the Prince's role was so small. Questioned on the subject by the Christian Science Monitor's Frank Daugherty in 1938 he responded:

"I suppose that's legitimate criticism, but it might help if people knew we were plain scared. None of us knew how those drawings of human figures on the screen were going to be taken. We were prepared for any sort of ridicule. We had an idea we could put them across, and if we could it meant the removal of our biggest limitation; we were willing to face the ridicule for that. Today, human characters don't scare us at all. We know we've licked 'em."

In fact, the depiction of the Prince is imperfect. As he climbs from his pristinely white horse to kiss the sleeping Snow White there is a moment when his image "shimmers", as a result of a fault in the accuracy of the drawing. This was discovered too late for the fault to be amended, and Walt had to allow the film to be released with this imperfection. Oddly enough, it is a flaw audiences hardly ever notice.