What is Color Theory and how does it pertain to you as a Decorative Artisan?
In short, Color theory is the art of combining colors based on the color wheel to reach a desired result.
And the Color Wheel, you ask? The color wheel is an organized illustration of the three kinds of colors - primary, secondary, and tertiary colors into their combined colors.
The three Primary Colors, or colors that cannot be created by mixing others together, are red, yellow and blue. These are the only true colors to exist in nature and every other color is made from.
To get the Secondary Colors you will mix the Primary Colors together - when you mix red and yellow you get orange, when you mix yellow and blue you get green, and when you mix red and blue you get violet.
The third tier of colors are called Tertiary Colors or the colors you get when you mix Primary colors with Secondary colors - red-orange, yellow-orange, yellow-green, blue-green, blue-violet and red-violet.
You may notice there is no blending of complimentary colors, or colors across from each other on the color wheel - red and green, yellow and violet, blue and orange - just colors next to each other. That's because mixing complimentary colors will cause them to neutralize. If your paint is too red you can add some green (yellow and blue) to it and it will tone down the redness, this is a trick used in makeup applications as well. I used to worry about my dark undereye circles and a peach corrector would be recommended because the orangey undertone would help neutralize the bluish purple shades under the skin before coming in with a concealer.
Theoretically, if you were to mix red, yellow and blue together you would get black. But if you're at all familiar with tinting usually they end up as a dirty brown and that's because it's rare, if not impossible, to make true colorants of any kind. True meaning no other undertone can be found. Red is red, not red orange or red blue - the easiest example of this for those of us that wear makeup can be found in lipsticks, they're never just red are they? They always lean one way or the other.
"That's great, but how does this help me as an artist?" the helpful thing about color theory for you on a job especially is sometimes products you used on your sample look perfect in your studio and then let's say when you get on site suddenly the plasters are too warm (yellow) and now you're stuck between losing a "bad" batch of plaster and a day or 2 of work to remedy the color or seeing if the client will just go with it. Often times it comes down to lighting, but sometimes people aren't willing to compromise on either issue. Color Theory says violet (red and blue) will cut the warm yellow undertones and your plaster will be more neutral. Now, with violet especially, one drop will likely change the whole bucket and it won't turn the plaster violet unless you add too much!
Learning how colors react together takes time, I'm still learning 6 years in!, and figuring out what undertone a paint swatch may have isn't always incredibly obvious. A great resource that I come back to time and time again to practice this skill is Golden Color Mixer which has many of the colorants available from Golden Artist Colors (yes, that Golden) that can be digitally mixed together to see how ratios of different colors behave together.
Here you can see how those complimentary colors react in a 1:1 ratio. Some of the browns are definitely warmer, and it will depend on the undertones of the colorants you are using, but tinting and being able to problem solve on the job can really save you time and money.
I hope this quick run through was informative and interesting! If this is something you're interested in further exploring I may write a more in depth catalog on it or consider teaching a class.