CODIJY Pro Photo Colorization - Add colors to black & white photos and recolor images with surprizing ease!
Voxly - Voxly – Color by Number 3D is a relaxing, de-stressing, and addictive coloring app designed for kids and adults who love to color.
DeOldify - Open-source deep learning project for colorizing and restoring old images
Daily Pixel - Daily Pixel – Color by Number, Happy Pixel Art developed and published by Magic Arts.
Pigment by ShapeFactory - A unique way to explore color using lighting and pigment
Recolor - Recolor – Coloring Book is an amazing app that allows you to enjoy the simple relaxation and joy of coloring.