Personalizing content is often why people dive into customization. I noticed a few examples online with different colors for their nodes in Dynamo. It turns out we can adjust the theme and colors by altering the DynamoColorsandBrushes.xaml file here: Autodesk 2019\AutoCAD 2020\C3D\Dynamo\Core\UI\Themes\Modern. Unfortunately, to see the updates we have to close out Dynamo and Civil 3D then reopen them both.
Brian Chapman Design 