So, here is an old Lemon I painted back in 2004. I learned in this assignment that what we paint is its own color as well as the color of what is around it. In this case, the Lemon is also orange and blue, or 'yellow-orange' and 'green' you could say. It was a fascinating study for me. Enjoy.
(P.S., this lemon was a plaster sculpture painted pure yellow...so real lemons would have even more nuances of color to handle. But this was simplified)