Scientists create secret formula to make plants fluorescent. The formula is sprayed onto flowers and plants which are then placed next a special light to make them glow (blah blah sciencey stuff. ALL I CARE ABOUT IS SPARKLING GLOWING FLOWERS!
Split the stems into strands, place each one in food colouring and get rainbow flowers. Only catch must have a very large round stem in order to achieve this. Or you can inject white roses as they grow.