在python bokeh中，如何在没有js的情况下交互地修改fill_color的字段？

from bokeh.plotting import figure, show
from bokeh.models import CustomJS, ColumnDataSource
from bokeh.layouts import row

source = ColumnDataSource(data=dict(fill_color=['blue', 'green', 'red']))

p = figure(width=400, height=400)
p.rect(x=[1, 2, 3], y=[1, 1, 1], width=0.9, height=0.9, fill_color='fill_color', source=source)

callback = CustomJS(args=dict(source=source), code="""
    var data = source.data;
    var selected_color = cb_obj.value;
    data['fill_color'] = [selected_color, selected_color, selected_color];
    source.change.emit();
""")

color_select = Select(title="Select Color", options=['blue', 'green', 'red'], value='blue', callback=callback)

show(row(p, color_select))