Comment 11 for bug 1818550

All of the color settings can bet changed in the layer manager. The grid style can be set in the configuration dialog for the appropriate main window. It will most likely be 2 years before KiCad 6 is released but the removal of the legacy canvas from the development branch is slated to happen soon. Once it's gone, the motivation to fix this bug in the 5.1 branch will be almost zero. I suggest you start using the modern canvas now so you can learn to configure and use it. If you have any questions about using KiCad, you should ask on the KiCad user forum at https://forum.kicad.info/.