There are a couple of ways you can make black lights using LED strips. The first and easiest method is to purchase good quality lights that come with a remote to create a custom color. Once you have them set up and turned on, make a DIY color by pressing the red 25 times, followed by the blue 25 times. However, you can manually create a similar effect on a white LED strip using clear tape and a blue and purple marker, but it is much more time-consuming. You'll need to cover every individual light with tape that you've colored blue. Then repeat with another layer of blue tape, followed by a third layer of tape that's been colored purple.