Each tube of 50 glow necklaces have an assortment of brilliant colors. Once they start glowing, these glow stick necklaces will last you all night. They will glow super bright for 8-12 hours. Then, they will start to fade out but may continue to emit some light for up to 36 hours. Inside the glow light necklaces are two chemicals that emit light or glow when they are mixed together. Bend the glow necklace to activate. Just shake it up and presto -- it starts glowing like magic! FlashingBlinkyLights Glow products are non-toxic. PLEASE NOTE: Prior to activation, glow in the dark necklaces will not necessarily appear the color that they actually glow when activated.