An apparatus for measuring a color of a non-solid colored sample, the apparatus comprising: an integrating sphere comprising: a sensor port; a sample port; a light port; a light source positioned near the light port for illuminating the interior of the integrating sphere; and a plurality of registration marks affixed to an interior surface of the integrating sphere, outside a periphery of the sample port, wherein the plurality of registration marks comprises: a first registration mark (202 1) and a second registration mark (202 2) collectively providing four constraints for correcting up to four registration errors in an image, the registration errors including displacement along two axes, image dilation, and zoom; a camera positioned near the sensor port arranged to capture a plurality of images that include a sample positioned at the sample port and the plurality of registration marks; a processor to control operation of the light source and the camera; and a plurality of color filters positioned between the integrating sphere and camera, wherein the processor is configured such that each image of the plurality of images is captured using a different color filter of the plurality of color filters; wherein an optical axis of the camera passes from the camera, through at least one filter of the plurality of filters, and through the integrating sphere from the sensor port to the sample port. an integrating sphere comprising: a sensor port; a sample port; a light port; a light source positioned near the light port for illuminating the interior of the integrating sphere; and a plurality of registration marks affixed to an interior surface of the integrating sphere, outside a periphery of the sample port, wherein the plurality of registration marks comprises: a first registration mark (202 1) and a second registration mark (202 2) collectively providing four constraints for correcting up to four registration errors in an image, the registration errors including displacement along two axes, image dilation, and zoom; a sensor port; a sample port; a light port; a light source positioned near the light port for illuminating the interior of the integrating sphere; and a plurality of registration marks affixed to an interior surface of the integrating sphere, outside a periphery of the sample port, wherein the plurality of registration marks comprises: a first registration mark (202 1) and a second registration mark (202 2) collectively providing four constraints for correcting up to four registration errors in an image, the registration errors including displacement along two axes, image dilation, and zoom; a camera positioned near the sensor port arranged to capture a plurality of images that include a sample positioned at the sample port and the plurality of registration marks; a processor to control operation of the light source and the camera; and a plurality of color filters positioned between the integrating sphere and camera, wherein the processor is configured such that each image of the plurality of images is captured using a different color filter of the plurality of color filters; wherein an optical axis of the camera passes from the camera, through at least one filter of the plurality of filters, and through the integrating sphere from the sensor port to the sample port.