Well having a binary choice between black-on-white and white-on-black is completely different than your asking for theming, as that sounded like syntax highlighting.
Based on the fact that the font 'Emoji One Color' glitches in the scripts editor the same way it does in the editbox when I set that as channel font, I'm assuming the script editor is drawn using RichText the same way the editbox is, so colorizing should be doable.
I'm not so sure a new color setting for the alt+K window would need to happen, but maybe something more in sync with whatever your existing theme is, so perhaps a setting in Editor Options to choose to have the editor colors match from your existing theme, such as from one of
$color(editbox text) and $color(editbox)
$color(normal) and $color(background)
$color(treebar text) and $color(treebar)
As for what colors if any would be changed for the row# column, it might be best to leave those alone?