Make 2 holes with a drill for glass (diameter about 0,8 cm). One in the upper part and one in the lower part of the vase.
Buy 5 meters of colored electrical cable of your choice. Some example here.
Buy some sheet of colored polypropylene. Best results with a thick sheet of at least 1,6 mm maximum 3 mm. Took mine here but it is 1,2 mm thick. Better search for something thicker ‘cos the upper clear part tends to bend.
Cut the polypropylene using the sketchup template I uploaded here.
Using a cutter, lightly score the polypropylene along the lines between blue and white surfaces and bend it at 90°