that's not true peepdel, all of the brands that WOW listed (Homeguard, Provia, and HMI) most certainly do offer the same color interior and exterior on a hinged fiberglass door. You can get paint, stain, etc, all factory finished on both sides. Same color on both or different colors.

For us, it depends on the room in which the doors are located, and whether or not we want to draw attention to them. We have the old multipanel doors that are a nice feature of our old house. All the trim in the house is painted much darker than the doors or the walls. In my office I painted the doors a medium color because they looked too bland painting them the same light color of the walls, but I didn't want them too dark, either. The exterior of the front door coordinates with the exterior house colors, and the inside coordinates with the LR colors. In the front den the doors are the same light cream we used on the inner trim of the windows, while the door frames are the same dark color we used on the outer trim/frame of the windows. If you want to de-emphasize the doors, paint them a color that makes them recede, such as the color of the surrounding walls. If you want to emphasize them, use a contrasting color that draws attention to them.

They have Certified Kitchen designers in Lowe's that can help you. If your Cabinet dealer dosn't have a certified designer on staff I would find a dealer that does. That sould be part of the service they are offering you when you buy the cabinets.

Sorry I need to see from further back and I also need to know where that door leads and why you can't use interior materials . The door placement is a bit confusing without context.