Real easy with good seps.... White base, flash, blue, red, gray(that gray has a big ole solid area of ink so I'd print it right before the flash), flash, top white. Having a good underbase so the top colors can fall nicely into the shirt is key as well as inks that allow for good transition from the base to the shirt fabric. This is super easy to sep in psd using rgb channels then making adjustments. Plenty of ways to print this as others I'm sure have a different approach but this is how I'd run it.