Meanwhile, continued analysis supported the reality of an orangeish tint throughout the scene, the atmospheric color resulting from small suspended soil particles. Several days after the first release, we distributed a second version, this time with the sky reddish. We smiled painfully when reporters asked us if the sky would turn green in a subsequent version. The initial images were unnaturally saturated, or rich in chrome. Reducing the saturation makes the scene appear more drab.
Most persons equate apparent color with hue.
However, changes in brightness and saturation can produce images which appear to be much different in hue. In order to do this it is necessary to examine, for each picture element, reflectances in all six bands, three in visual color and three in near infrared. The amount of off axis radiance for each channel is estimated by considering the radiance in the five other channels and developing an integrated spectral solution that satisfactorily accounts for the measured reflectances in all six channels. The reader may be thinking that problems of color reconstruction largely could have been circumvented by mounting on the spacecraft targets of known color. In fact, such an array of color chips was mounted and has been imaged.