There is nice guideline for material icons. Also the page contains Illustrator files with the temllate file, so the artist can make an icon the same style.
I am curius if there such a guide for Krita? If there is no such a guide I think it makes sence to create one and place on the website.
Motivation to have a guide: Even beginning artists will be able to produce a nice “in style” results. Also it will allow plugin makers to do consistent plugins with the main UI.
Also it would be good to have an open list (maybe as a topic) of icons “to design” maintained by developers. Then new contributors will ilimmidiately understand what to focus on. Instead of redesigining already existing icons.
There are som ediscussions already:
- Krita UI icon button style consistency feedback - #46 by novames00
- Krita UI Icons - To be proposed - #81 by noahdvs
The best one so far is this. However, this topic has a set of suggestions.
As for another outside exaples. Blender did a good job with icons. It is a good reference. Interstingly, it quite difficult to find icon guidelines for Blender as well.
The best shot:
https://wiki.blender.org/wiki/Source/Interface/Icons
And pretty good discussion here:
Again, I will emphasize that is nice to have single point of entey for a designer. The best place for my opinion is
Get Involved section.