Starting with the third season, the "Cold Squad" division was folded into a province-wide task force and its basement setting eliminated. Along with significant variations of the title sequence (Seasons 1–2, 3–6, 7), theme music (Seasons 1–2, 3–4, 5–6, 7), new sets (Seasons 3–6, 7), and change in McCormick's hair colour from auburn to blonde along with her wardrobe (in particular her jacket), these differences contributed to a considerable reworking of the series. The only character to appear in all seven seasons was Sgt. Ali McCormick.