Here’s the first brand I used and it wasn’t waterproof. After using both I would just stick with the non-waterproof ones bc there is no risk of water bc these are only used when the windows are closed. And they form better to the sides of the window on the corners. You might need longer strand depending how big your windows are.
MINGER LED Strip Lights 16.4ft, RGB Color Changing LED Lights for Home, Kitchen, Room, Bedroom, Dorm Room, Bar, with IR Remote Control, 5050 LEDs, DIY Mode https://www.amazon.com/dp/B07JP5375R/ref=cm_sw_r_cp_api_glt_fabc_YA0PXGKNSA3WEM1CKPGD?_encoding=UTF8&psc=1
Here are the waterproof ones if you would rather use them.
LED Strip Lights, HQVOIC 32.8ft Non-Waterproof Tape Lights Color Changing 5050 RGB LEDs Light Strips Kit with Remote for Home Lighting Kitchen Bed Flexible Strip Lights for Home Bedroom Decoration https://www.amazon.com/dp/B07XKYY11H/ref=cm_sw_r_cp_api_glt_fabc_YP4FPGT9Z5BEPYZRK5FB?_encoding=UTF8&psc=1
I also have them on smart plugs and control them by an app and have them come on at 7P and off at 11P. I went with this brand bc you got 4 plugs and they were cheap.
LED Strip Lights, HQVOIC 32.8ft Non-Waterproof Tape Lights Color Changing 5050 RGB LEDs Light Strips Kit with Remote for Home Lighting Kitchen Bed Flexible Strip Lights for Home Bedroom Decoration https://www.amazon.com/dp/B07XKYY11H/ref=cm_sw_r_cp_api_glt_fabc_YP4FPGT9Z5BEPYZRK5FB?_encoding=UTF8&psc=1
The only issues with either of these is that the smart plugs sometimes don’t receive the wifi signal to turn on/off so you just manually do it. And on of the led strips when it turns on doesn’t stay on the color purple and flips thru red, green, blue, white and I call it club mode, lol. I just need to buy a replacement for it. You can get them here if you need it.
DUNZHITECH 1-Port 44 Keys RGB IR Remote Control for 5050 2835 3528 RGB LED Strip Lights Output Voltage DC12V-24V LED RGB IR Remote Control https://www.amazon.com/dp/B08DNB6LQX/ref=cm_sw_r_cp_api_glt_fabc_T3HKSC65FB8TCZBX85MS?_encoding=UTF8&psc=1
E:fixed some words.
E2: I also leave the led tape up year round and remove the box and plug wires when not in use. You don’t even notice they are there. Good luck!
I dont have a Kallax, but I do have a similar cube shelf that I recently did lighting on! I used these lights along with this spool of LED cable. A couple pictures can be seen here https://imgur.com/a/eg6Rd1L
I used a small pocket knife saw to cut just enough material away for the led strip to pass between cubes.
I am very happy with how it turned out!