ipywidgets.Text background-color

This took some time to figure out so I'll post it here in hope it helps someone else. To set the color of an ipywidgets Text box using CSS, you need to:

• add a CSS class name to the Text widget
• render an HTML <style> block for an <input> element descendant of that class
• Set !important on the background-color, to prevent it being overridden by a later Jupyter-declared style.

For my case the Text widget was being included in a VBox, allowing the HTML widget containing the <style> to be included in the list.

data_input_style = "<style>.data_input input { background-color:#D0F0D0 !important; }</style>"
value_entry = ipywidgets.Text(value='')
value_entry.add_class('data_input')

children = [
    ...
    ipywidgets.HTML(data_input_style),
    value_entry,
    ...
]
ipywidgets.VBox(children=children, ...)