I'm tellin ya, you could do it with electroluminescent paper.  They come in various colors and you could technically splice them together with some easy soldering (or cirtuit pen or whatever) or just use one solid color for the whole thing.  They terminate in a battery pack or a power adapter 
https://www.amazon.com/Elastic-Electroluminescent-Glowing-Battery-Purple/dp/B01M8O4SPO/ref=sr_1_1?ie=UTF8&qid=1479419449&sr=8-1&keywords=electroluminescent+tape+with+a%2Fc 
https://www.amazon.com/Bingirl-Electroluminescent-Cuttable-Panel-Inverter/dp/B019GWSTC8/ref=sr_1_1?ie=UTF8&qid=1479419665&sr=8-1&keywords=electroluminescent+sheet 
http://www.instructables.com/id/How-to-Attach-or-Reattach-EL-Tape-Electrolumine/?ALLSTEPS