Also I can't remember the last time the Colts have played the Lions. I know it's been several years, so forgive me for the lack of knowledge of your team.
The Lions have only played the Colts once on Thanksgiving, and that was back when they were in Baltimore. The year was 1965 and that game ended in a 24-24 tie (before Sudden Death Overtime was instituted).
Since 1984, the Lions and Colts have met 4 times and each has won twice.
In 1985 the Colts won 14-6. The Lions won in 1991 (33-24) and in 1997 (32-10). The last time these teams met was 2000 and the Colts won 30-18.