Dear apple,
apologies for this late reply, maybe you have solved it already by yourself.
To visualize the results, you should be able to simply threshold it by thresolding it with your “fwe_pvalue.tsf” file.
I can not better explain it as it is formulated here:
https://mrtrix.readthedocs.io/en/latest/fixel_based_analysis/displaying_results_with_streamlines.html
This entry in the forum here might also help as it provides insights into loaded files in mrview:
Best, Lucius