and not RBY?
Red, Blu and Yellow are the primary colors.
But Red Green Blue are settings on my monitor. Why isn’t my monitor/TV etc RGY? And How does RGB combine to make yellows?
Go play with your moniter controls. If you have a PC and are using Windows, you can control the color of your background by changes the RGB values.
Pigment primary colours are actually cyan, yellow and magenta (red, blue and yellow are primary school art class approximations); light primary colours are red, green and blue.
This is because pigments work by absorbing light and only reflecting back a part of it, so every time you add a pigment of another colour, you’re reducing the total range of colours of light being reflected - pigment primaries are subtractive.
Light primaries are additive - every different colour of light you shine on a surface (or out of it, in the case of light emitting devices), adds to the total range of colours of light being perceived.
Magenta(reddish), cyan(bluish), and yellow are the primary colors used for subtractive color mixing. Red, green, and blue are the primary colors used for additive color mixing.
The monitor produces red, green, and blue colored light. Shining a red, blue, and green light together produces white light (you’ve added up enough light to cover the visible spectrum). Red, green, and blue are also what the three types of cones in the eye respond to.
Subtractive color works by filtering out light leaving only a particular color. If you combine the primary color filters magenta, cyan, and yellow you get black (you’ve filtered out enough light to block the visible spectrum).
The Hyperphysics site explains color in a lot more detail, with diagrams.
Or, what Mangetout said.
Red and green makes yellow.
If you draw on the computer you get very used to it after a while.
There are 3 types of color-detecting cones in your eyes; each type responds to a different range of wavelengths in the light spectrum. Very roughly, these types “peak” at red, green, and blue, correspondingly.
If an intermediate wavelength comes in (say, yellow), then more than one type of cone will get excited. In the case of yellow, for example, both red & green cone types will become excited, and the brain sees the color yellow.
So, every color can be conceived with a mixture of red, green, and blue wavelengths, because in a way that’s all we can see.
I’ve always wondered what a hypothetical person with more than 3 types of cones would perceive if they saw a TV. Probably would look monotone or washed-out to them.
There’s some research indicating such people actually exist – Google tetrachromats.
I could have sworn I read an article once about some women who were tetrachromats, but Wikipedia says it’s never been confirmed in mammals.
If human tetrachromats really existed in modern times, there’d be a LOT more literature on them. Color science is a very big field spanning many industries.
Thanks,
So, if I’m working with paint, I can mix red, blue and yellow together to make the colors, but if I’m projecting an image I would use RBG. Is that about it?
Cecil himself has addressed this:
If blue, red, and yellow are primary colors, why do color TVs use blue, red, and green?
Arjuna34
More or less, yes. As noted above, you’d need cyan, magenta and yellow paints (plus black to make dark colors). We only call them “red,” “blue” and “yellow” to schoolchildren who haven’t learned as many proper color names.
You might also note that Cyan, Magenta, Yellow and blacK combine into what is called CMYK four-color printing. Check out the margins of your newspaper sometime on any page where color is printed; you might find little crosshairs in cyan, magenta, yellow and black. These crosshairs are supposed to line up so that each color in the printing process aligns properly with the others, but often newspapers are imprecise enough to see each crosshair color separately.
I’ve actually drawn color renderings using only cyan, magenta and yellow Prismacolor pencils (with black for shadows). You can get quite a range of color if you practice your color blending.
>So, every color can be conceived with a mixture of red, green, and blue wavelengths, because in a way that’s all we can see.
This isn’t actually true, because our three kinds of cones each have broad ranges of sensitivities, and the ranges overlap. Moreover, our red cones also have a small sensitivity peak in the blue. Mixing any triad of real colors can only create colors inside a triangle in “color space”, having its angle points at the real colors locations. The human color range is a somewhat rounded and bulging triangle in this space; no real triangle covers all the points inside our bulging triangle.
Color experts, such as the “CIE”, create imaginary colors called X, Y and Z such that X + white = pure red, y + white = pure green, and Z + white = pure blue. These colors can’t physically exist, but some linear combinations of them can, and they fill out the human “gamut” or range of colors. Mathematically this works out just fine and solves many problems in color science.