DataTable HTMLTemplateFormatter cell size

Currently, one can set the background color and other CSS style elements of DataTable cells using the HTMLTemplateFormatter. However, this assigns a child <div class> to the parent <div class slick-cell> which has padding set to 4 px and border set to 0.25 px. Thus, there’s always going to be a bit of white background behind the color, as seen in the answer to https://stackoverflow.com/questions/50996875/how-to-color-rows-and-or-cells-in-a-bokeh-datatable.

It would be nice to be able to color an entire row without that white margin showing up. With the parent having that padding, I don’t think this is possible. One could set the width of the child to something like 110% in the HTMLTemplateFormatter, but this would only push the background color in one direction.

I think it would be better for the parent’s padding and border to be set to 0 px, and then the child (which the user gets control over with HTMLTemplateFormatter) gets to be anywhere the user wants it. So I’d like to change https://github.com/bokeh/bokeh/blob/b56543346bad8cdabe99960e63133619feaafbb7/bokehjs/src/less/widgets/tables.less lines 49, 50, and 52 to 0 px.

Is this the kind of thing I need to make a custom model for, or should I put in a pull request?