A couple of weeks ago I asked in BA forum if it was possible to customize the Blender 2.80 icons. After the answers, I learned to compile Blender and started to analyze the icon sheets of the current version and of the 2.79. At the end, with Inkscape, I was able to create a new sheet for 2.80 containing the majority of 2.79 icons. It has been a quite time-consuming task, because there is not 1:1 correspondence between the two original sets, each composed by hundreds of icons. I tried to fully respect the note of the author: “Icons must be used only for functions they were designed for, in order to maintain GUI’s internal integrity”. For this purpose I found very helpful the references provided by mkbreuer on BA forum [https://blenderartists.org/t/icon-reference-sheets-2-79-2-80/1162781]. When possible, I substituted the monochromatic icons of 2.80 with the colorful ones of 2.79. For new features that don’t have previous correspondences I left the monochromatic icons.
This is the result (being a new user I can only post a single image):
I made the new sheet primarily for my personal use, but if someone is interested I can happily share it with the community, maybe with a little how-to for using it during compilation. But before making the step, for correctness, I would like how to manage the licence. I saw in the 2.79 sheet that the author used the GPL license, while the sheet for the 2.80 sheet is now released under the CC. Obviously I want to give the original author full credit for the work, I only make modifications, but I don’t know which is the best way, because here I read that is not possible to use GPL content in CC work [https://creativecommons.org/share-your-work/licensing-considerations/compatible-licenses/].
I am not expert in this sector, so I would like to ask you, and maybe directly the author, the best way to choose.