In large bowl, combine 2 cups sugar, brown sugar and margarine; beat until light and fluffy. Add chocolate, vanilla, food color and eggs; blend well.
Lightly spoon flour into measuring cup; level off. Add flour, baking soda and salt; mix well. Cover with plastic wrap; refrigerate 1 to 2 hours for easier handling.
Heat oven to 350°F. Lightly grease cookie sheets. Shape dough into 1 1/2-inch balls; roll in 1/4 cup sugar. Place 3 inches apart on greased cookie sheets.
Bake at 350°F. for 8 to 12 minutes or until set. (Cookies will puff up, then flatten during baking). Cool 1 minute. Remove from cookie sheets.