On sale for a pretty good price is this RGB LED Lightstrip that has a Bluetooth controller so that you can change the colours with your phone and an IR remote if you don't want to use your phone. It's powered by USB and the strip has an adhesive back. Available in lengths from 1m to 30m.
I personally use a few strips behind my desk, under my kitchen cupboards and behind the TV and they're great.
Choose Emitting Color: Bluetooth Control and select your length. Anything 5m or above will incur a shipping fee.
AU$ based on current Mastercard rate, GST inclusive and stacks with cashback.