I have done it without cleaning and it worked for me. At the beginning of course will have some paint from the previous color. You need to stray it until you see the next color
Short term storage, that's fine. But if you're not using it frequently, I recommend storing it using pump armor, cleaning the filters, spray tips, and main gun. When not using it frequently, the pump can malfunction unless storing it with pump armor. Graco has some helpful storage videos that go through the full details. Hope that helps! Thanks for your question.
