Colors Are Not Vibrant

I always order a sample order before I place a large order. The samples looked great, the colors popped. When my order arrived I could instantly tell the colors were duller. This is the second order that the colors were dull. The first time this happend our stickers were just black and white and it wasn't that noticeable to make a fuss. We have ordered many stickers previously with no issues. It has just been our last two bulk orders.