I think you are asking the wrong question. When I first started painting, I had that kind of mind set. It is the way most people are taught. The way that I learned, was to have your background colors paler, and to use a blue, gray, or a purple. Muted these colors will recede. Then, as you come forward in the painting you add more intensity to the colors, and add more detail. Don’t get me wrong, I haven’t totally discarded this principle. The problem with most beginners is that they are afraid of dark values (dark colors). When a beginning artist paints in this manner, they tend to end up with a pale and washed out painting. I was a beginner once. I remember not being able to paint green trees. I would start painting the leaves with a green, after all trees look green. Grass is also green, so I would paint the grass a different green. Before you know it, the whole painting was green and totally hideous, because there weren’t any darks.
I have an old friend who doesn’t know anything about art. Years ago, when I wasn’t yet making a living with my paintings, I showed him some of my latest paintings. He said , “They are nice, but why would I want them“. That is the question you should be asking yourself. What can I do to this painting to make somebody want it? Drama! You need drama, not depth. You need the painting to pop. You do this with dark against light. Without a dark, dark, the light isn’t very bright. The brighter you want the light to be, the darker you have to make the dark. If you concentrate on lights against darks, I promise you, your paintings will have depth. You are going to have to use your imagination here. First, think of a painting as a group of objects or planes. Imagine cutting each object or plane out ,and then stacking them from front to back, to make a 3D image. In the back you have the sky, then the clouds on top of the sky. then the distant mountain, the, distant yellow field, the closer green field, etc. Now lets go from the back to the front, and paint this painting in layers of light against dark
If you focus on the lights and the darks, I promise you will improve your paintings. If one plane is light the next plane has to be dark and visa versa. If the plane or object is a middle value, you can go either way. Make it a lot lighter or a lot darker. You choose!
Here is the painting without the lines.