Cheers, Luv!
I thought I'd make available the PSD file of one of my colored cel-shading works because it's actually not that complicated in terms of layer structure. May this help you learn, experiment and be inspired!
The file costs 100 
and can be purchased on the right of the page just here. ==>
All the layers of the file are named for a better understanding.
I arranged the file so that it can be opened properly in Photoshop, Manga Studio/Clip Studio Paint and Paint Tool Sai. Other programs accepting PSD files will open it as well but a slight difference in colors may possibly occur.
Finally and as usual, if you happen to be inspired and to integrate some of my techniques in your work then please do show me your results. I loooove when this happens.
Enjoy!