Using your thumbs and forefingers, flatten one small gumdrop to 1/8-inch thickness, lengthening and widening to form a petal shape. Dredge lightly in granulated sugar to prevent sticking as you work. Repeat procedure for desired number of petals. Place petals on a wire rack, and let stand uncovered for 24 hours. Holding each petal between your thumbs and forefingers, use your thumb to press the lower center portion of the petal inward, cupping the petal. Gently curl the top outer edges of the petal backward.
Plan ahead when making rose petals: They need to stand for about 24 hours to stiffen slightly before adding the finishing touches that make them look so realistic.
Use a single brightly colored gumdrop to shape the petals, or knead two colors together—such as red and white to make pink. Add more white to soften the color and create a paler pink, or add a pinch of yellow to highlight a portion of the petal. Experiment with different color combinations to see which you like best. For the prettiest petals, don't over-blend the colors or be too exact with the shaping.
Dampen fingertips to prevent sticking when kneading gumdrops together. (A folded paper towel moistened with water works great—it's like a stamp pad for your fingertips.) It's easier to work with just three or four gumdrops at a time when blending new colors. After kneading several together, dredge lightly in sugar, and divide the mixture into small gumdrop-size portions for shaping individual petals and flowers.