Let me start by saying that I'm a huge fan of Vittoria tires. In recent years I used their gum wall (appearing) Evo Corsa tires with good results.
Their Graphene G+ are marketed with an implication that you can buy them with either appearance (black or gumwall). In reality you can get them in black or dingy white. The dingy white tires do not remotely provide the appearance of traditional gum walls (light yellow-brown-tan). Worse yet, they discontinued making any tires that will replace the gum wall appearance of their previous tires
Neither the photos or the text on their website make any mention of the fact these tires do not provide a gum wall appearance. Because it's a fairly new product, first time consumers will only become aware of this deception when the tires arrive on the UPS truck. Like me, they will likely put these ugly tires on their bike hoping they might look OK. They won't unless you're looking for a dirty white wall look.
In summary, Graphene appears to be a worthwhile product. Just don't order their gumwall-looking tire thinking it will look OK as a replacement for their previous gum-walls.