Chat JS seems to be offering dark and light mode support according to this GitHub PR: https://github.com/chartjs/Chart.js/pull/8685
The question is, how to call colorMode: "auto" in ChartKick as ChartJS default is none...
The mr got closed, so there is no colorMode
option in chart.js. To achieve a dark/light mode you will need to adjust all of the colors yourself.
The main colors you want to adjust are data.datasets[datasetIndex].backgroundColor
and options.scales[scaleId].grid.color
. That will make most of your chart be visible on light and dark