code: def dropdown_click(attr, old, new):
      active_dropdown = dropdown.value  ##Getting dropdown value
  
      if active_dropdown == "red":
          c = ["red", "red", "red", "red", "red", "red"]
      elif active_dropdown == "green":
          c = ["green", "green", "green", "green", "green", "green"]
      source.data = dict(x=x, y=y, color=c)
  
imports: from bokeh.io import curdoc
  from bokeh.layouts import row
  from bokeh.models import ColumnDataSource, Dropdown
  from bokeh.plotting import figure
label_desc: Use image node_id 1 for calling a global function with example usage: dropdown_click(attr, old, new) without return types