Thank you, Chris, for yoursuper quick response!

While I can use both of my ROIs as overlays in MRICroGL, my challenge lies in adjusting the transparency of one of them while keeping the other opaque in the render view. Specifically, I'm using these overlays to visualize connectivity results, where one ROI serves as the seed and the other as the target (activation area).

I aim to make the seed ROI appear slightly transparent (like in "image1" in light red and on top the opaqe green) while keeping the target ROI fully opaque. However, when I load them as overlays, I find it challenging to adjust the transparency of only one of them without affecting the transparency of the other or the underlying template ("image2".

I tried also "draw->advance->create overlap image" option to combine the rendered brain with the seed ROI thinking then to overlay the other ROI (target) on top of them. Unfortunately, this approach distorts the template template, and the colors are not preserved as desired ("image3").

I would appreciate any further advice or alternative methods you might suggest for achieving this visualization goal, either within MRICro or using any other tools you have in mind.

Thank you very much for your assistance!

Tammar