F150 camper shells are custom ordered to match the paint of the truck. Using the available F150 XLT colors for 2016, options include blue flame, race red, ingot silver, ruby red and Oxford white. The F150 XL color options are similar but also include a shadow black. When a camper shell is ordered at dealerships such as Topper World or Ultimate Camper Shells, the technician accesses the color code from the vehicle to make the match.
On new Ford F150 trucks, this is usually all that's needed for a perfect match. On older trucks, the color codes are still used, when available, but the actual paint color may have to be tweaked to allow for paint fade. Sunlight, inclement weather and even washing over time can wear away the clear coat and alter the shade. In some cases, it's just easier to respray the truck and camper shell together.
The other option is to order an aluminum camper shell instead of a painted fiberglass one. These are available in a variety of configurations -- many of them work-related. Simple toppers or camper shells are also available, with or without side, back or front windows. They rarely have a cohesive, all-in-one unit look, but if used on F150 trucks painted Oxford white or with a lot of chrome trim, the aluminum shells do work well.