Roses come in many different colors, but not blue. Fortunately, you can make your own blue roses at home. This can be done for pleasure, or as a science experiment for younger children. When dyeing a rose blue, start off with a white flower. The white will take to the blue dye the best.
Fill a glass three-quarters of the way with warm water.
Add a packet of flower preservative to the water. If you don't have one from your garden center, you can add an aspirin and 3 tbsp. sugar, which will accomplish the same thing as the flower preservative.
Drip 10 drops of blue food coloring in the water, or use blue floral dye. If you use floral dye, read the packaging label to know how much to add to the water. Stir the water.
Take the leaves off of the part of the rose stem that will be submerged into the water. You don't need to remove leaves that will be above the water line.
Set the white rose in the glass of dyed water.
Wait 24 to 48 hours for all of the white rose petals to turn blue.