Combine number learning with coloring and get creative with one of the best online coloring games called Color By Number. a format that has been popular in physics coloring books for a while. The entire drawing that you have to draw, such as the pig, will be separated into brackets, and for each bracket, there is a number. The number is associated with a color, so click the color associated with that number, and then click the bracket that matches that color. Continue doing so until you have filled all the points with color and the entire image has been drawn.