References: https://arxiv.org/abs/2005.09007 https://blog.floydhub.com/colorizing-b-w-photos-with-neural-networks/ https://saifgazali.medium.com/cell-nuclei-segmentation-using-vgg16-unet-and-double-unet-eafb65bb959a https://arxiv.org/pdf/2006.04868.pdf