How do I know what the true color of the object that I am trying to paint is? Where do I find that color since there are so my variations within the object?
A simple thing to remember is that when deciding what the color is, simply look for the middle value. It's not the dark or the lightest part of the object. Rather, the true color resides in the middle where the color is not affected by the bright light or the darker shadow.
Everyone instinctively looks for the middle value to register color, but most people are not aware that it is in the middle that they naturally locate it as the color of the object.
Once the color is determined the artist can then use that mixture as the base color to work off of to make the variations need to build the three-dimensional form.