In a tutorial on Krita 4, I've seen that there's a tool that can mix different colors. For example, red and brown. Unfortunately, I can not find it anymore. Can a Kritajan help and write me where to find a description?

A simple tool would be a blender brush preset, such as Blender-Basic which is in the Krita default resources. Just type 'blender' in the search filter box at the bottom of the brush preset docker.

The documentation has a good overview of colour mixing techniques: https://docs.krita.org/Mixing_Colors

The Link:
Not Found
The requested URL /Mixing_Colors was not found on this server.

Apache/2.4.7 (Ubuntu) Server at docs.krita.org Port 443

Yes, the manual got moved a few hours ago to a new format: https://docs.krita.org/en/general_conce ... ixing.html

We haven't been able to set up a 404 page or anything else even!

The new manual is great! Well done.