Brown is a shade of orange. Orange was intermixed with black to create brown. By adding white to brown we create tan. We have created a tint from a shade. As we add one color to another each step is a tone.
Tone is any step as the color passes from a light to dark shade or vice-versa.
For instance, as we add yellow to red we create orange. Orange is actually a tone of red. As we increase or decrease the addition of yellow to red, each step is a tone. The dyes and pigments used by the furniture finishing trade are not pure colors. Even the whites and blacks we use are not pure.