1. A color retrieval neural network for retrieving standards from a database of standards based upon color values of a sample, said color retrieval neural network comprising: an input layer having input nodes for receiving input data related to the color values of the sample; an output layer having output nodes for providing output data related to the standards in the database; first weighted connections connected to said nodes of said input layer, each of said first weighted connections having a coefficient for weighting said input data; and wherein a non-linear relationship exists between said input data to the input layer and output data from the output layer, said non-linear relationship interrelating color values of the sample at different angles with standards in the database.