Thanks for the contribution, @valeryozenne! Sorry I've been a bit slow off the mark - too much going on at the moment...

I've had a go at your branch, and it seems to me that your -tractography.colour works fine, at least in terms of setting the colour for a second tractogram? There was a glitch in the handling of colours in the [0,1) range, but that was easily fixed - see the changes on the mrview_add_two_new_command_line_option branch, and feel free to merge them into your pull request if you're happy with them.

For example, if I run this command:

./build bin/mrview && bin/mrview data/fa.nii -tractography.load data/CST_L.tck -tractography.colour 0,0,1 -tractography.load data/CST_R.tck -tractography.colour 1,0,0

this is what I get:

which is what I would have expected... (?)

Regarding your -tractography.tsf_colourmap option, I don't see a problem either - it all seems to work as expected? When you say the GUI has not been updated, are you talking about the colourmap shown on the button to change the colourmap? Because that button doesn't get updated when you change the colourmap, it always shows the hot colourmap. But when you click it, you can see that the correct colourmap is indeed showing as the selected one in the drop-down menu.

So as far as I can tell, it's more or less good to go (with minor fix I mentioned above)!

Thanks a lot, I merge your changes, and this is working. Best

Good to hear. I'm guessing you'll now need to push your changes back to this pull request, and then mark it as not draft so we can merge it. 👍

Hi @valeryozenne,

Any chance of updating your GitHub user account with a profile picture?
These appear both in the version changelog that we post on our community forum, and on the MRtrix3 website front page.

Cheers
Rob