Changing line_color interactively - Cross post from git bokeh issues

https://github.com/bokeh/bokeh/issues/1942

Hi

I hope cross posting is allowed:

The examples show that one can change the data on a plot using the text box entry or a drop down menu. Is it possible to change the line_color on a chart in the same manner?

I have tried adjusting population _server example in the same way - but with no luck.

Kind regards