We are very pleased to announce that the new AFNI Message Board framework is up! Please join us at:
https://discuss.afni.nimh.nih.gov
Existing user accounts have been migrated, so returning users can login by requesting a password reset. New users can create accounts, as well, through a standard account creation process. Please note that these setup emails might initially go to spam folders (esp. for NIH users!), so please check those locations in the beginning.
The current Message Board discussion threads have been migrated to the new framework. The current Message Board will remain visible, but read-only, for a little while.
At this time, no. You'd have to do a "fill" in some external image editing program (e.g., gimp). I suppose it would be possible to modify the "Zero Color" control in the image viewer to work with RGB images (as the renderer generates), but for the nonce ....