Gradients in the style of LSD afterimages were a core part of SC2 and early SC3. Sadly, gradient functionality mostly went away with the port to QT. :(((((
Unfortunately yes. The classes Gradient and HiliteGradient are still documented, but without functionality. For good reason it was not highest priority in the days of the change to Qt, but I always hoped it would come back. GUIs with gradients are much more fun to work with.
I checked the other day to access the 90s part of the mailing list (because history), and the website is now offline (though it is captured in the waybackmachine)… I wonder if we should also archive this somewhere on our end? I assume James McCartney got tired of paying for the domain or forgot about it, but it doesn’t look like it’s a huge amount of data.
EDIT: nvm this seems to be a problem on my end… Sometimes I can access the website normally, sometimes not.