As the Lady of the Lake wanes in power throughout the story, with each sighting we see her "necklace of fish" reducing in number. Similarly, Queen Mab's hair grows grey as her power wanes. Merlin, being a mortal who contains magic within him, only wanes in appearance with the passage of time.
Because of his strong performance as Merlin in this film, Sam Neill was offered the role of Gandalf in The Lord of the Rings: The Fellowship of the Ring (2001) but turned it down due to complications with filming Jurassic Park III (2001).
Nickolas Grace and Robert Addie, best known for their roles as the Sheriff of Nottingham and Sir Guy of Gisbourne in Robin Hood (1984), have a cameo scene together in this mini-series, a nod to fans of the beloved 1980s fantasy show.