The coloring system in ColorFil is exactly like that of other similar apps. At the bottom of the screen you will see all the available color pallets, so all you need to do is tap the color of choice and then tap the white space you wish to color in. It's that simple.
All the changes you make to your drawings will automatically be saved, meaning that there is no need to worry about losing all the improvements you have made. You can also work on as many pictures as you want at the same time. In other words, you can start to fill in whichever picture you wish, and finish them at your own speed.
ColorFil is a fabulous coloring app for adults, offering dozens of images completely for free, along with a great selection of colors.
Android 4.0.3 or above required