engly-saxo

Is it known how many colours exist?

Modern computer monitors can display tens of millions of colours, nonetheless is this representative of the entire range of colours?

Splarnst

I would conjecture that it's infinite because there are an infinite number of possible wavelengths within the visible range.

Imaginary Mark

It is known that there are infinitely many colors. They are frequencies on the electomagnetic spectrum that are visible to our eyes.

Since the computer monitor can display only finitely many colors, obviously it can't display them all. So the question is: is 24 bits sufficient to display the range of colors that are distinguishable by the human eye? This I don't know.

(BTW: 24 bits are typically used to represent Red (0-255), Green (0-255) and Blue (0-255)).

I just did a little experimenting with mspaint and I couldn't really tell the difference between colors that were different by only one.

doc_simon

24bit gives you 16.7 million colours, IIRC.

Interestingly (I guess), if you have a black and white image (greyscale) you can get away with only 256 shades to represent the image.

Yggdrasill

A colour arises from the wavelength/frequency of the light. For instance, "red" is light with an approximate wavelength from 625 nanometers to 740 nanometers in a vacuum. (perceptions may vary) But you can have some light that has a wavelength of 701.3228374274372707540725734872378365473583465 nm; it's still red, and because you can have an infinite number of decimals, you have an infinite number of colours.

drewjmore

I'm going to toss the Q-bomb here:
Quantum theory actually places an upper limit on the number of discreet frequencies of light. Perhaps invoking that word will invite someone who can provide the number.

NZSkep

probably not, because within an upper and lower limit there are still an infinite amount of choices if you keep dividing

Mageth

There appears to be some confusion with "colors" and "points on the EM spectrum".

Is the number of "colors" the number of points on the "visible light" portion of the EM spectrum? In which case, the number is essentially, if not actually, infinite?

That doesn't seem quite right, as many "colors" that we perceive are actually mixtures of different wavelengths in the visible range of the EM spectrum, are they not? For example, white is a sum of all spectral colors. And then there's black, which is the absense of light.

So, is the number of "colors" instead defined by what is perceivable/distinguishable to the human eye? If so, I think that number should be a discrete number, with some maximum range.

NZSkep

you're probably right, but then the number would be dependant on which person looked at the colours.

Mageth

Perhaps, but there should be some maximum range as to what colors are distinguishable by the human eye.