Sorry, in the next alpha we have actually removed the paint menu, because it has been confusing people. (Understandably – They thought it wasn’t working for them somehow). So it will be hidden until we finish the paint features.
Since Alpha 5 the plan has been to first publish Animation Paper 5.0. (Which is very close now). Then, following close to immediately after, a free update to 5.1 – will include all the coloring features. This is the good and faster way forward.
Are you in need of coloring now? Because, you can easily do your coloring in other software, like Photoshop, Krita or any other paint package. You can export your animation as a sequence of png’s, with file name numbering, so holds and copies (clones) are recognised and you don’t need to color the same drawing twice. Also check out the OCA format (Open Cell Animation format), which is a way of exporting your whole project and import it to other software with all timing etc intact. More about OCA here: https://animationpaper.com/animation-paper-oca-export-for-pc/ (It works for both Mac and PC)