Because you need to cut it twice, equally the same size, it doesn't matter if you "recolor" it in VM, it can be any color you want, because the color that you will get is the color you put into the cutter.
If it were my project, I would just convert everything to the same color, then put in a polylines that will place your slices where you need to color transition to be.
There are often times when I work in just basic primary colors to differentiate weed boxes vs. design, and neither of those colors have anything to do with the color vinyl I put in the machine. (ie. the design in the software is black, the weed box is red (in the background), and the color vinyl that goes into the machine is white).
But if you really, really must have the design itself (solely in your software) be in two colors as you're are seeing in your photo, then you'll need to get the design, put the polyline slices in it, copy and paste a second copy, then node edit out the appropriate portions you don't need, the piece is back together. Going to the honest, it's not worth the time and effort. Just do one design, doesn't matter what color, then cut it twice with the two different vinyls.