If you're throwing a party, or simply want your flowers to match the colour-scheme of your house or dinner-do, simply wrap an appropriate coloured strip of paper around a straight-edged vase. Experiment with different patterns, different lengths and widths, and placing the paper up high or down low. Stick the paper in place with double sided tape, and add decorative embellishments if desired. You'll easily turn your floral arrangement into a party-perfect Spectacular!
Note: you can wrap a vase with sloping or splayed edges, but the paper will wrap in a shape more like a man's old fashioned neck-collar rather than a straight strip.
If you're more clever than I am, consider making a vase-cuff out of fabric, using ribbons or buttons to hold it in place... and don't forget to send me photos or links to your blog posts so I can shout out about how clever you all are!