DotPlot: `fill_cutoff` clarity

[j-andrews7]

For DotPlot, the fill_cutoff parameter documentation is a bit unclear:

fill_cutoff
A numeric value specifying the cutoff for the fill column. By default, the fill direction is "up". If TRUE, the fill direction is "down". When the direction is >"up", the values less than the cutoff will be filled with grey. When the direction is "down", the values greater than the cutoff will be filled with grey.

Is there a way to change fill direction?