He got his costume from an action figure.
In Detective Comics #566 (July 1986), we see Mr. Freeze with the following design:
This design appeared earlier in the year in Kenner's third wave of the Super Powers Collection:
For comparison, here's what he looked like in his previous full appearance (July 1984):
The suit was being used at least until 1991, when it appeared in Who's Who in the DC Universe #12 (September 1991).