So I ran into a bunch of difficulty styling the table and search box dark and I didn't want to invest any more time into it as I had other features I wanted to get done first, so I ended up implementing a System theme, using MacOS defined colours.

Note that I am now colouring on an individual basis the cells so we can easily spot (for example) an instrument that has been trending up for the last 90 days but took a recent dip in the last 9.