By Andrew Gould Colin Kaepernick attended Michigan’s spring game Saturday as an honorary captain and held a throwing exhibition at halftime. As the free-agent quarterback attempts an NFL comeback, he showed significant appreciation for Jim Harbaugh. Speaking with WXYZ Detroit’s Jeanna Trotman (h/t Austin Nivison of 247 Sports) after his workout with undrafted receivers, Kaepernick reflected on his bond with Harbaugh, who spent four years as Kaepernick’s head coach with the San Francisco 49ers. “Coach Harbaugh, he’s always been phenomenal for me,” Kaepernick said. “From the time we met at the c…