Working with XPresso - MAXON CINEMA 4D R16 Studio: A Tutorial Approach - page 420

Figure 13-12 Choosing Red from the flyout in the XPresso Editor
10. Click on the output port (red square); a flyout is displayed. Choose User Data > Yellow
from the flyout, refer to Figure 13-12; the Yellow output port is added to the Traffic-
Lights node, refer to Figure 13-13.