change default colour

[AlePaff]

Hi, really like your code, is there a way to easily change de red-blue default color? i like it, but i would like to try some diferent palette.

[spfaus]

As far as i can see, there is no configuration option for it. (might be a nice addition)
If you are willing to change the source, I would recommend to try and change the color definitions in the _css variable in Kanji_grid.py.
https://github.com/tsudoko/kanjigrid/blob/master/Kanji_grid.py#L31

I just briefly looked over the source so I apologize if that is not the right approach.