When the visual appearance of a component is considered, the Revit structural connections are not as easy to manipulate as one would expect. Some discussion on the subject can be found in the following post.
https://forums.autodesk.com/t5/revit-structure-forum/stell-connection-material/m-p/7989395#M26130
Essentially there is no way to manage the material of the plates per the type of connection. Each plate within each connection must be selected to override.
Sampie, from Prokon has kindly posted the idea on the Revit Ideas page. If you would like to assign materials more easily to Revit structural connections, please vote for this idea at the following link.
https://forums.autodesk.com/t5/revit-ideas/steel-connection-material/idi-p/9181608
In larger projects, it is clearly not worth the time to change the material of every steel plate in the connections (they must be set per instance). Hence, one would have to investigate if it is possible to do so using Dynamo. I did a cursory scroll through the Revit API but could not immediately find a solution that exposes itself. Neither could I find a reference to a node that might be of interest.
Unless there is a compelling case for the material to be changed, my recommendation would be to leave the structural materials of the connections well alone. Or otherwise ask an intern or someone not critical to the modeling and analysis of the project, so that it may be done cost-effectively and without wasting valuable time.
If you need help adopting Revit or BIM in your practice, please contact Micrographics so we may be of assistance.
