You might be able to achieve such a look with the Clouds generator from Apple Motion. (This is different from the one that ships with FCPX.) But you can create a Final Cut Pro Generator from it using the settings below.
If you set the 1st, 2nd and 3rd layer strength to 0 and the 4th layer strength to 1.0 you'll get the right sort of frequencies. You'll then need to choose or create a gradient with different color bands in it.
It also looks like they're mixing several layers of it with similar settings. You could try different blend modes and opacity levels for different effects.