Methods, systems, and non-transitory computer readable storage media are disclosed for utilizing an edge prediction neural network and edge-guided colorization neural network to transform grayscale digital images into colorized digital images. In one or more embodiments, the disclosed systems apply a color edge prediction neural network to a grayscale image to generate a color edge map indicating predicted chrominance edges. The disclosed systems can present the color edge map to a user via a colorization graphical user interface and receive user color points and color edge modifications. The disclosed systems can apply a second neural network, an edge-guided colorization neural network, to the color edge map or a modified edge map, user color points, and the grayscale image to generate an edge-constrained colorized digital image.