1. Add 1-1/4 cups boiling water to orange gelatin mixes in medium bowl; stir 2 min. until completely dissolved. Pour into 8-inch square pan sprayed with cooking spray. Repeat with remaining boiling water and grape gelatin mixes. Refrigerate 3 hours or until firm.
2. Meanwhile, melt chocolate as directed on package; cool slightly. Pour into small resealable plastic bag; seal bag. Cut small piece off one bottom corner of bag; use to squeeze chocolate onto waxed-paper covered baking sheets to make 12 spider webs or other Halloween shapes. Refrigerate until chocolate is firm.
3. Cut gelatin in each pan into 1/2-inch cubes. Layer orange gelatin cubes, half the COOL WHIP and grape gelatin cubes in 12 (6-oz.) plastic cups. Refrigerate until ready to serve.
4. Top parfaits with remaining COOL WHIP and chocolate decorations just before serving.
* Special Extra: Before filling cups, pipe 1 oz. melted chocolate onto inside of each cup to make a design or write a spooky message, such as "boo." Refrigerate cups until chocolate is firm, then fill as directed.
* How to Make Spider Webs: For spider webs, use 2 oz. melted chocolate to draw a cross on waxed paper-covered baking sheet, then draw an "x" on the center of the cross; connect all ends of lines with additional melted chocolate to resemble a spider's web.
* How to Make Ghosts: Drop COOL WHIP by spoonfuls onto each dessert to resemble a ghost. Add 2 miniature chocolate chips to each for the eyes.
* Recipe courtesy of Kraft Kitchen