MITRA Forum Question Details

​Generally, a paint made from a single pigment will be brighter (have higher chroma) than a mixture of pigments, but it depends on the components of the mixture and how they are prepared. In my experience, Cadmium Orange is brighter than an orange mixed from cad red and cad yellow, but some synthetic organic pigments, when mixed with a pigment that increases opacity (white, for example), result in a mixture that appears brighter than cadmium orange straight from the tube. That doesn't, however, necessarily mean the mixture will have the same tint strength, that it will work as well in mixtures, or that it will have that same brilliance in a work of art.​

I am not getting the notifications for all post, so I apologize for the later response. Matthew covered this well, but I do want to beat the deceased horse.

In subtractive color mixing (the only type of color mixing associated with paint) every time an additional pigment is added, a portion of the spectrum is absorbed and not reflected. This does not mean that everything is equal. A mixture of two very highly saturated colors that are biased in a similar direction can often create a paint that is far more intense than another single pigment that is inherently less intense. In practice a mixture of phthalo blue green shade with a highly saturated organic yellow of a lemon or slightly greenish bias will create a super saturate green. This will be far more intense than viridian but probably not as saturated as a phthalo green.  

In practice, it is not always the best practice to create the most saturated hues (unless you are searching for that intensity) and then have to cut the intensity by adding gray or a compliment. Over time one develops the intuition about when and which colors should be mixed to create the desired hue, value, and saturation. This journey does continue for one’s lifetime.

Brian is so right that it takes a lifetime (at least) to refine the sensitivities and skill involved in mixing and using color. It's by juxtaposing colors, surrounding them with contrasting mixtures, that concepts like "value" and "chroma" become meaningful. Intensity or "brightness" is created on the canvas by a relationship between a color and a neutral, or its complement. This perceived intensity peaks when the juxtaposed colors are close to the same value (lightness and darkness), and even more when that value approaches the "home value" of the more chromatic color.(Home value is the degree of lightness/darkness at which a color is most chromatic.) When we learn to control contrasts between colors, then even an earth color can seem smolderingly intense.

All of the above is excellent advice.  

One more thought to add to the discussion is that the word "bright" can be ambiguous; it generally refers to high chroma/colorful (i.e. a bright red fire engine versus a dull red barn door) but is also sometimes applied to values (i.e. a bright white).  So when a student says "I want to make the lemon in a painting brighter" I ask, "Do you mean increase the chroma, lighten the value - or both?".  High chroma and light values, in and of themselves, can contribute to a 'bright' and luminous effect; however, as noted, chromas and values are always in relationship with other colors/values within a painting, and those relationships have a tremendous effect on 'brightness'.   For example, a high chroma, high value cadmium yellow may actually appear "brighter" set against (and thus contrasted with) a neutral, low value black (versus surrounded by and thus in competition with other similarly high chroma colors).   

Overwhelmingly the two most common issues I see in student work is (a) they don't understand or even know (nevermind represent) the light source that's illuminating subject matter (what direction the light is coming from, its effects on subject matter), and (b) they don't have a full range of values represented in the overall design (they have light and middle values with no darks; or dark and middle values with no lights).  Feeling the lack of "brightness", they add ever more and higher chroma to a painting.  However a value problem isn't solved with chroma, particularly since many high chroma colors are middle values (which is the one value almost never missing)!  

So, in my experience, the simplest way to "brighten" an image is to understand and represent the effects of illumination within the image; and make sure you have a full (but organized) range of values (i.e. see Rembrandt, among others).  Then, adding a few, select areas of high chroma are like icing the cake.  Illumination and values are the key to luminosity and "brightness", in my experience.  

If the artist in question isn't interested in representing a light effect - just high chroma - then hopefully they're acquainted with a co-primary palette.  As Brian pointed out, for high chroma one must combine colors that incline towards one another on the wheel.  Bruce MacEvoy has an Artist's Color Wheel available for free download at https://handprint.com/HP/WCL/cwheel06.html that places actual artist's pigments on a wheel.  

Koo Schadler​

​Don't get me started on color contextuality/simultaneous contrast. I spend weeks discussing this in my Color Mixing and Matching class. Koo, I tend to use intensity or saturation to describe chroma. The term chroma is certainly accurate, but by connotation, many of my students seem to equate chroma with hue. I avoid the term brightness because it does not really describe the physical phenomena we are alluding to.