What is the best way afford ably of course to do blue lighting under the counter and living room ?

I want to add a little modern touch to my living room and kitchen with blue lighting. I want to have blue light shine up the wall under the flatscreen tv and under my kitchen cabinets. I want it to be a nice deep blue and want any input anyone may have that has done this. I'm curious if there may be fluorescent style lights that are "extremely" affordable to both buy and run. I've looked around on the web but have only found the outrageously priced way to do this. There has to be a simple and affordable way to do this and get nearly the same look. Also input from someone who has done this will save me time and money to begin with.....Thanks for your input.