The factory paint is a base coat with a clear coat finish. The base coat is a thermoset acrylic enamel, not a urethane. The clear coat is urethane. The paint code which indicates the original factory paint color is located on the Service Parts Identification Label (also known as the "RPO [Regular Production Option] Sticker") on the left front fender well near the brake master cylinder.
The paint code is the last item listed and is in the form WA-NNNN (N = any number). If a Fiero had the "ground effects", two numbers will be listed, usually with a "U" and "L" for upper and lower colors. The number(s) shown is the Fisher Body "WA" paint number. (Fisher Body is the division of GM that produced and painted the car body.) Use this number when buying matching paint from any paint supplier. Touch-up paint suppliers such as PlastiKote and Dupli-Color also use this number as a cross-reference. Use the cross-reference manual found by the paint display in your auto parts store to obtain the correct spray can or bottle for your car. Or if you are repainting the entire car, give this number to your painter.
Due to aging of old paint, new paint will not be the same shade. If a Fiero is repainted we suggest use of the newer two-part urethane systems even though one-part acrylic systems may be cheaper. If you are a do-it-yourself painter, the Kirker brand (kirkerautomotive.com) of urethane paints is economical and decent quality. Many painters recommend premium paints such as DuPont and Sikkens for top quality results.
A helpful web site for touch-up paints is http://www.paintscratch.com/