It looks like we could
If you compare the chief to the Spartan 4’s piece by piece, you notice EVERYTHING is different. From gauntlets to shins to feat to fingers to neck to footprint etc. It goes on, the customisability is definitely going further and better.
I wouldn’t get my hopes up on it. The MC is only a SPARTAN II. The multiplayer spartans are SPARTAN IV’s. The visor pattern could have just changed. I bet you’ll be able to customize visor color, but not anything else about the visor so much. That’ll probably vary depending on the helmet.