CODIJY Pro Photo Colorization - Add colors to black & white photos and recolor images with surprizing ease!
Daily Pixel - Daily Pixel – Color by Number, Happy Pixel Art developed and published by Magic Arts.
DeOldify - Open-source deep learning project for colorizing and restoring old images
Coloring Book for Adults - Coloring Book for Adults is a 100% free coloring app that offers an addictive way to de-stress and get creative.
Pigment by ShapeFactory - A unique way to explore color using lighting and pigment
Adult Coloring Book - Free Pictures, Best Zoom, Most Color, New Tools, and No Subscription fee.