theme helpers: improve bokeh background

[gordonwoodhull]

On a whim, I asked Claude if it could fix the missing background color problems in theme_colors_bokeh()

It only hallucinated one key:

AttributeError: unexpected attribute 'text_color' to Legend, similar attributes are title_text_color, label_text_color or inactive_hatch_color

Here is the code with Claude's recommended fixes, and that key fixed as suggested in the error.

Seems to do it!

def theme_colors_bokeh(bg, fg):
  from bokeh.io import curdoc
  from bokeh.themes import Theme

  curdoc().theme = Theme(
    json={
      "attrs": {
        "figure": {
          "background_fill_color": bg,  # plot area
          "border_fill_color": bg,      # area between plot and outer edge
          "outline_line_color": fg,     # border around the plot
        },
        "Grid": {
          "grid_line_color": fg,
          "grid_line_alpha": 0.2,       # make grid lines subtle
        },
        "Title": {
          "background_fill_color": bg,
          "text_color": fg,
        },
        "Axis": {
          "background_fill_color": bg,
          "axis_label_text_color": fg,
          "major_label_text_color": fg,
          "axis_line_color": fg,        # axis line color
          "major_tick_line_color": fg,  # tick marks
          "minor_tick_line_color": fg,
        },
        "Legend": {
          "background_fill_color": bg,
          "title_text_color": fg,
          "label_text_color": fg,
          "border_line_color": fg,
          "border_line_alpha": 0.2,
        }
      }
    }
  )