# How many colors are there? **URL:** \ **Category:** Factual Questions\ **Created:** [May 24, 2009, 6:32pm UTC](https://boards.straightdope.com/t/how-many-colors-are-there/497480 "2009-05-24T18:32:49Z")\ **Posts on this page:** 5\ **Page:** 3
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [May 26, 2009, 10:31pm UTC](https://boards.straightdope.com/t/how-many-colors-are-there/497480/41 "2009-05-26T22:31:32Z")
> [@EdwardLost](#): > > […] it might be possible to develop anesthetic eyedrops that selectively deadened one or two of your cone types. You could see colors you had never seen before. They would be neurologically new, but your brain would probably map then onto colors you were already familiar with. I’ve been pushing a related but more accessible idea on my friends, or whatever you call people who will mostly listen to you. Stare at a deep red light that does little to stimulate your blue sensors, until they are tired. Then quickly change to a deep blue light, which would normally stimulate your red sensors too. Since they are tired now, you will see a larger blue:red ratio than you have ever seen before. That would be a new color, one which can’t be seen except fleetingly. ---
**Author:** ![The\_Hamster\_King](https://avatars.discourse-cdn.com/v4/letter/t/8edcca/32.png) [@The\_Hamster\_King](https://boards.straightdope.com/u/The_Hamster_King)\ **Post date:** [May 26, 2009, 10:45pm UTC](https://boards.straightdope.com/t/how-many-colors-are-there/497480/42 "2009-05-26T22:45:35Z")
> [@Napier](#): > > I’ve been pushing a related but more accessible idea on my friends, or whatever you call people who will mostly listen to you. Stare at a deep red light that does little to stimulate your blue sensors, until they are tired. Then quickly change to a deep blue light, which would normally stimulate your red sensors too. Since they are tired now, you will see a larger blue:red ratio than you have ever seen before. That would be a new color, one which can’t be seen except fleetingly. That’s a totally cool idea! ---
**Author:** ![natalie\_kiko](https://avatars.discourse-cdn.com/v4/letter/n/b9e5f3/32.png) [@natalie\_kiko](https://boards.straightdope.com/u/natalie_kiko)\ **Post date:** [May 26, 2009, 11:03pm UTC](https://boards.straightdope.com/t/how-many-colors-are-there/497480/43 "2009-05-26T23:03:06Z")
I’m not exactly positive on a precise number of colors, but our eyes can see somewhere around 20,000. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [May 26, 2009, 11:48pm UTC](https://boards.straightdope.com/t/how-many-colors-are-there/497480/44 "2009-05-26T23:48:05Z")
> [@Chronos](#): > > Quoth **Mangetout** :For all the more we know about anything relating to the Planck scale, this at least we know is false. The Planck acceleration is in fact a ludicrously _large_ acceleration, such that all known accelerations in the Universe are significantly smaller than it. So you could in fact Doppler shift your quantized frequencies by any amount you choose. > > This might begin to give some appreciation for why it’s so hard to construct models of physics with quantized time and space. I didn’t realise that, but now you mention it, it makes sense. How can something move 1 Planck length in more than 1 Planck time (without it being halfway at some point in between)? It makes nonsense of the idea of quantized space (or time) ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [May 27, 2009, 2:14am UTC](https://boards.straightdope.com/t/how-many-colors-are-there/497480/45 "2009-05-27T02:14:46Z")
Seven. ROY G BIV. According to a _Trivial Pursuit_ question I missed 25 years ago. But I’m not bitter. [Previous page](https://boards.straightdope.com/t/how-many-colors-are-there/497480.md?page=2)