1. An apparatus for assessing a color characteristic of a gemstone, comprising: an optically opaque platform, wherein the platform has a surface configured for supporting a gemstone to be assessed; a daylight-approximating light source shaped to at least partially enclose the platform, wherein the light source is designed to provide uniform diffused illumination to the gemstone on the platform; an image capturing component, wherein the image capturing component is positioned at a predetermined angle relative to the platform surface that supports the gemstone, and wherein the image capturing component and platform are configured to rotate relative to each other; and a telecentric lens positioned to provide an image of the illuminated gemstone to the image capturing component.