Color Mixing tips (Best for those who always face problems while mixing the color)

• Use mixtures rather than colors straight from the tube for more interesting color. For example, mix blue and yellow to make green or add other colors to tube green to modify the color.
• Most color-mixing problems come from overmixing. Mix very lightly on the palette or directly on the support to prevent this, and once the color is down, leave it alone.
• Some books tell you to use no more than three colors in a mixture, but the problem isn't usually concerned with the number of colors; it's a matter of which colors you use. Paint characteristics and your choices of colors determine how they will mix. Refer to the article on Split-Primary Color Mixing to learn how to mix clean, bright color every time.
• Complements (opposites on the color wheel) create color vibrations and enhance each other when placed side by side. When mixed, they neutralize each other.
• To lower the intensity of a color, mix it with its complement or Burnt Sienna rather than black, gray or sepia. These colors tend to deaden mixtures.
• For high-intensity mixtures avoid the third primary. The third primary is the complement of the mixture of any two other primaries and will lower the intensity of this mixture. For example, you know that red and blue make violet; however, a warm red (which has yellow in it) makes a dull, low-intensity violet when mixed with blue, because yellow is the complement of violet. 
• Keep the use of white paint to a minimum. Rather, exaggerate the color you see in the subject when transferring it to the canvas.
• It is easier to modify it with white paint later, when the canvas is covered and you compare it with the subject.
• Chances are the color will not be as strong as you had thought and will require little or no changing. 

• You will also find it valuable to experiment with making a color darker or grayer by combining it with its opposite instead of the obvious black. 

• Black has a place in the mixing of color, but use it sparingly until you have learned the possibilities of the primary and secondary colors.