1. A method of imaging a single unstained sample, comprising: identifying a group of control samples corresponding to a target stain, wherein the control samples include spectroscopic data and images of a plurality of samples that are stained with the target stain; generating a neural network from the group of control samples, wherein the neural network is a feed-forward neural network trained using reduced spectroscopic data from the group of control samples as input, wherein the neural network generates bright-field color data as output; obtaining a spectroscopic image of the single unstained sample; reducing dimensionality of the spectroscopic image, thereby generating reduced spectroscopic image data; and generating an output computed stain image from the reduced spectroscopic image data using the neural network, thereby imaging the unstained sample to represent of the target stain.