Brandy, 23, burst clear in the 62nd minute, rounded Colchester goalkeeper Mark Cousins and whipped the ball into an empty net to register his second goal for the club, lifting Walsall above Colchester in the table.
Smith said: "He always seemed to have the extra yard to get away from players, but in the first half I thought it was going to be one of those days for him when his chances didn't go in and he tormented their full-back.
"I have always said Febian had potential and now he has a platform at this club to show it. He's energetic and full of enthusiasm, but doesn't live off the fact that he was a young starlet at Manchester United."
Brandy's missed a number of games early in the season with a hamstring strain and his second goal for the club handed Colchester their fifth successive defeat, enabling the Saddlers to leapfrog them with a three-point advantage.
Smith, whose side had wasted two-goal leads at home four times this season, said: "I think we deserved to win and thankfully we got across the line this time."
Brandy dropped out of the game for 18 months after being released following 12 years as a youngster at Old Trafford, but a surprise call from Sir Alex Ferguson re-ignited his determination to do something in football.
He said: "I had wondered whether to carry on in football, but when someone like Sir Alex takes time out of his schedule to call you and tell you to sort your head out and get back in the game, you listen."