Our RGB primaries are a simplification that comes from availability of pigments. While blue was originally a very rare and valuable pigment made from precious stones, it was still more available than magenta or cyan, which are made synthetically.
All of the following is taking paint mixing into mind.
When looking at a continuous colour wheel:
You can see where each colour sits on the spectrum.
When you consider a RBY palette, we are limited to essentially the colours in this triangle:
Mixing a vibrant Purple or Green is often difficult with a basic rby colour palette, and a Magenta or Cyan is impossible. We define a primary colour as “foundational colours that cannot be created by mixing other colours”, which means that CMY are real primaries, right? Well, if we look at the CMy palette:
We DO get a wider range of colours, but you’ll notice that a true purple, green, blue, and red are still outside of our range. You can get a pretty close red with Yellow and Magenta, but it will never be as vibrant as a pure Red pigment. So then Red is a primary?
When painting, you should use the colours that you need for the work, and mix from there. The ‘primary colours’ are a tool to teach students the theory of colour mixing. It is not a perfect guide, but teaching complex colour theory to novice painters is just intimidation. Most people get an intro to art, learn RBY, and then leave art, don’t think about it again until a TikTok titled “school LIED to you” introduced CMY.
EDIT: this is from the perspective of an artist. I am not an expert, and certainly got something wrong in here, but the primary argument has always annoyed me
In printing it’s a little different, but if you need an exact color you can add it to the process, much like adding a varnish or other fancy finish.
Orange was always a problem when I was a designer. It had to be specific, you had to send a Pantone chip along, hope it hadn’t faded or changed color over the years (or buy new ones constantly) and then it still came out different than planned.
Are you confusing subtractive and additive colors? For subtractive (used for e.g. paints) you use CMY, with white being what you get with no colors and black is a perfect mix of full CMY. With subtractive each color takes light away.
Additive (used for lights) works the other way round: the base colors are RGB. No light colors is black, all light colors is white. Adding another color in additive adds more light.
So, sure, if you use additive base colors in a subtractive process, you will get garbage and vice versa.
The real fascinating thing is that Impossible Colors exist, which means it’s kind of impossible to actually represent all colors or impossible to precisely represent them.
Imo it seems colors are relative to how our brain and eyes are adapting to their current field of view, meaning the color you experience is not fully dependent on the light an object actually reflects nor the activation of your rods and cones but is dependent on the way your brain processes those signals with each other. Ergo, you can’t actually represent all colors precisely unless you can control every environmental variable like the color of every object in someone’s field of view and where someone’s eyes have been looking previously etc.
If you want to be even more pedantic you could say no metre stick is exactly 1 metre long according to the current definition of a metre. If you want to be scientific then all of them are within some reasonable range like 1.000 ± 0.002 m. If you want to be historic then at one time there was a perfect metre stick
In 1799, the metre was redefined in terms of a prototype metre bar. The bar used was changed in 1889, and in 1960 the metre was redefined in terms of a certain number of wavelengths of a certain emission line of krypton-86. The current definition was adopted in 1983 and modified slightly in 2002 to clarify that the metre is a measure of proper length. From 1983 until 2019, the metre was formally defined as the length of the path travelled by light in vacuum in 1/299792458 of a second.
After the 2019 revision of the SI, this definition [of the metre] was rephrased to include the definition of a second in terms of the caesium frequency ΔνCs.
“Yeah! The real primary colours are CMY!”
Also bullshit.
Our RGB primaries are a simplification that comes from availability of pigments. While blue was originally a very rare and valuable pigment made from precious stones, it was still more available than magenta or cyan, which are made synthetically.
All of the following is taking paint mixing into mind.
When looking at a continuous colour wheel:
You can see where each colour sits on the spectrum. When you consider a RBY palette, we are limited to essentially the colours in this triangle:
Mixing a vibrant Purple or Green is often difficult with a basic rby colour palette, and a Magenta or Cyan is impossible. We define a primary colour as “foundational colours that cannot be created by mixing other colours”, which means that CMY are real primaries, right? Well, if we look at the CMy palette:
We DO get a wider range of colours, but you’ll notice that a true purple, green, blue, and red are still outside of our range. You can get a pretty close red with Yellow and Magenta, but it will never be as vibrant as a pure Red pigment. So then Red is a primary?
When painting, you should use the colours that you need for the work, and mix from there. The ‘primary colours’ are a tool to teach students the theory of colour mixing. It is not a perfect guide, but teaching complex colour theory to novice painters is just intimidation. Most people get an intro to art, learn RBY, and then leave art, don’t think about it again until a TikTok titled “school LIED to you” introduced CMY.
EDIT: this is from the perspective of an artist. I am not an expert, and certainly got something wrong in here, but the primary argument has always annoyed me
In printing it’s a little different, but if you need an exact color you can add it to the process, much like adding a varnish or other fancy finish.
Orange was always a problem when I was a designer. It had to be specific, you had to send a Pantone chip along, hope it hadn’t faded or changed color over the years (or buy new ones constantly) and then it still came out different than planned.
Well written!
Yes we can use any colors as “primary colors”, I use 6 when I paint (plus burnt Sienna & Umber because I’m lazy).
The colors you chose lets you mix up paints in a gamut, a gamut of colors is what you can get from those “primaries” that constitute said gamut.
Cheers.
Are you confusing subtractive and additive colors? For subtractive (used for e.g. paints) you use CMY, with white being what you get with no colors and black is a perfect mix of full CMY. With subtractive each color takes light away.
Additive (used for lights) works the other way round: the base colors are RGB. No light colors is black, all light colors is white. Adding another color in additive adds more light.
So, sure, if you use additive base colors in a subtractive process, you will get garbage and vice versa.
The real fascinating thing is that Impossible Colors exist, which means it’s kind of impossible to actually represent all colors or impossible to precisely represent them.
Imo it seems colors are relative to how our brain and eyes are adapting to their current field of view, meaning the color you experience is not fully dependent on the light an object actually reflects nor the activation of your rods and cones but is dependent on the way your brain processes those signals with each other. Ergo, you can’t actually represent all colors precisely unless you can control every environmental variable like the color of every object in someone’s field of view and where someone’s eyes have been looking previously etc.
Pedantic, but anything measurable and continuous is impossible to precisely represent. π/e meters for example.
If you want to be even more pedantic you could say no metre stick is exactly 1 metre long according to the current definition of a metre. If you want to be scientific then all of them are within some reasonable range like 1.000 ± 0.002 m. If you want to be historic then at one time there was a perfect metre stick
Wait, what changed in 2019?
https://en.wikipedia.org/wiki/Metre
And here I thought the primary colors were RGB
RGB are the additive colors (light projected) CMYK are the subtractive colors (light reflected)
Any set of colors can make a primary color palette. It’s just that we most often mean for human eyesight.
Even then, when talking about perception, because the response of red and green comes in our eye overlap we need imaginary colors to uniquely express them. https://upload.wikimedia.org/wikipedia/commons/thumb/e/eb/CIExy1931_ProPhoto.svg/1280px-CIExy1931_ProPhoto.svg.png
There are different sets of primaries used when we talk about screen, print, light, and paint.
Most people learn RBY through painting, whether as a child, or in art classes at school, and assume it applies to all colour.