I use two kinds of modeling tools in my form studies:
A commercial magnetic spoke-and-hub tool called Dyna-Magz. This tool works great for quick studies and smaller forms. However, for large complex studies it is too heavy to stay intact as a form’s node count increases. The small strut size also makes it difficult to work the model with your hands as the complexity grows. So, there is a practical limit to form complexity here. The kits come with multi-colored struts. In my modeling, unless specifically noted, forms are created with arbitrary colors.
For larger, more complex, build-outs I use a modeling system I developed and placed into the public domain called:
‘Compensating Skeletal Geometric Modeling System‘ : https://patents.google.com/patent/US20040158999A1/en
It uses light-weight strut material with a strong attachment mechanism so it can support large build-outs. The struts can compensate length to a small degree to get past certain hurdles. It is intuitive, easy and fast in build-out, and importantly, easy and fast in model take-down. The strut length I use is about 7″ so it is easy to get your hands inside and out of the model to work with. In sum, it makes explorations easy and fun.