Tip No 1: Add Dark to Light
It takes only a little of a dark color to change a light color, but it takes considerably more of a light color to change a dark one. So, for example, always add blue to white to darken it, rather than trying to lighten the blue by adding white.
Tip No 2:Add Opaque to Transparent
The same applies when mixing an opaque color and a transparent one.Add a little of the opaque color to the transparent one, rather than the other way round. The opaque color has a far greater strength or influence than a transparent color.
Tip No 3: Stick to Single Pigments
For the brightest, most intense results, check that the two colors you are mixing are each made from one pigment only, so you’re mixing only two pigments. Artist’s quality paints normally list the pigment(s) in a color on the tube’s label
Tip No 4: Mixing the Perfect Browns and Greys
Mix ‘ideal’ browns and greys that harmonise with a painting by creating them from complementary colors (red/green; yellow/purple; blue/orange) in the palette you’ve used in that painting, rather than colors you haven’t used. Varying the proportions of each color will create quite a range.
No 5: Don’t Overmix
If, when you mix two colors together on a palette, you don’t mix and mix until they’re totally, utterly, definitely combined, but stop a little bit beforehand, you get a far more interesting result when you put the mixed color down on paper or canvas. The result is a color that’s intriguing, varies slightly across the area you’ve applied it, not flat and consistent.