Testing wavelet cross coherence against 1/f or white noise

I am asking a lot of questions lately and appreciate the help! I am about to finish my defense in neuroscience but am pretty new to Matlab. I found Torrence and Compo, and other's use of wavelet cross coherence and a monte carlo method of significance testing, but it's against red noise, because they are interested in geoglogical phenomenon I work with EEG and really need to compare it to white noise. I see it's possible to do that with an AR model. My problem is I don't know how to modify their code, even though it's fairly user friendly, in order to change their 'generate rednoise' m file for a 'generate 'white noise' m file. I've tried to change the parameters, but I actually am not convinced I know what I've done. Can anyone help? If someone can, I can post or email the code I have from the Aslek Grinstead code from the UK geological society. I would really appreciate any advice! Kim