Evaluation of camera or scanner image capture usually includes the selection of reference color test objects. For image capture, since the optical characteristics are known, the intended camera color-encoded image data are compared with the corresponding idea values. However, for critical scene content, such as human skin, the color patches may not sample the encoded color space efficiently. In addition, the colorimetric sampling by the target, its spectral-reflectance characteristics may differ from those of important scene or object elements. We address the selection of color test patches for both colorimetric and spectral criteria. Results are shown for the imaging of skin tones and include an analysis of likely variability.