1. A system for scanning a surface comprising: an imager having image sensor pixels that each acquire images in each of at least a first image color and a second image color; a focuser that varies focus of the imager with respect to the surface; an illumination assembly constructed and arranged to simultaneously provide a first illumination type in a first illumination color recognized by the imager as the first image color and a second illumination type in a second illumination color recognized by the imager as the second image color, and a focus pattern, projected on the surface, in a focus illumination color recognized by the imager as the focus image color; and a focus process that reads image pixel data from the imager in the focus illumination color and that controls the focuser based upon the image pixel data in the focus illumination color.