vanilla in medium bowl. Beat at low speed of electric mixer until well blended. Scrape bowl. Beat at high speed for 2 minutes, or until smooth and creamy. Divide frosting into 4 small bowls. Add different food colour to each bowl, one drop at a time, until desired shade is reached. (One or two drops should be sufficient to achieve a soft, pastel colour.) Top cookies with frosting and sprinkle with coordinating coloured sugar crystals. Makes: About 3 dozen cookies ----