Add a twist to the regular finger paint by using chocolate pudding and Jell-O instead. Purchase cups of ready-made pudding for kids to stick fingers in. Choose the color Jell-O you like or get multiple colors. Mix one box of Jell-O with 2 tbsp. of hot water to form a paste. Let the concoction cool before letting kids spread the squishy mess on paper.
Play dough is fun to squeeze through fingers and play with. A 4-year-old can make this mixture with an adult's help. In a bowl, mix one packet of drink mix, 1 cup flour, 1/2 cup salt and 1 1/2 tbsp. oil. Pour 1 cup boiling water into the mixture and knead. Let the play dough cool in the refrigerator. Use small rolling pins and animal-shaped cookie cutters to create a play dough zoo.
Cornflour gloop begins as a solid and then melts through the child's fingers to leave him wondering what happened. Put 2 cups of cornflower in a bowl and constantly stir in about 1 cup water until it will not absorb any more. Add a few drops food coloring while mixing. Kids can let it drip onto black paper or play with it. When it dries, it is hard like chalk.
Place a large sheet of white paper in a box. Get different colors of acrylic paints and various sizes of balls for the activity. Kids take turns dipping the balls in the paint and smearing the balls on the canvas. Have races between the different sized balls dipped in paint. Tilt the box at an incline and let the balls roll. Observe what happens to various colors mixed together to create new hues. After the canvas is covered in paint smears, let it dry and hang to let the kids admire the artwork.