Assemble your own lightsaber from cardboard tubes, and paint the blade of your lightsaber anyway you want. Common lightsaber colours are purple, blue, green and red. You can buy the supplies to make your lightsaber from a craft store, or use items from around your house. For example, a cardboard tube from a roll of wrapping paper works well for the body of the lightsaber.
Paint the outside of the 3-feet cardboard tube any colour. This will act as the blade. Paint the outside of the 1-foot cardboard tube grey. Let both tubes dry completely.
Press a row of double-sided foam stickers inside the bottom of the small tube. Slip the large tube into the small tube. Line up the bottom of the tubes so they are even at the bottom. The taller tube will stick out at the top, which is the lightsaber blade.
Cut out six rectangles from the black foam. They should be 2-inches tall and half an inch wide. Spread glue on the back of the foam pieces. Press each piece around the bottom of the small tube. The rectangles should sit vertically with half an inch of space between each one.
Cut a nickel-sized red circle out of the foam. Glue it about halfway to the tube and about halfway up from the bottom of the small tube.