With the mini-graph-card, is it possible to have the gradient colors run vertical instead of horizontal? My card currently looks like this but I think it could look better if the color gradient was vertical...
Try use type: bar ( Basically it is Vertical ) thou you show a linegraph
Color gradient IS vertical here - from up to down (of vice versa if you like) as per defined color_thresholds (you have not posted a code, but it seems to contain color thresholds).

