When you see art that has shading like this (a darker shade of the lighter colors to signify shadows, the crust and pepperoni)
you can usually make those lighter/darker colors by printing on/off a base. This will depend on garment color though.
You can also print one of the darker colors under the shaded areas to act as a "darkening" base wow.
Basically there is a lot of ways to make the secondary colors happen. And there's a good number of secondary colors.
I'd offer to help but we're slammed. Retail I don't think we'd take this at less than 250 pieces or so.
Neon garments can be a nightmare to begin with, add in the number of flashes, probably a double base
for the neon inks, different grounds, etc, and you've got a no fun job in the make.