Which colored LED do you like as the "Power On" indicator?

Which colored LED do you like as the "Power On" indicator?

  • Red

    Votes: 82 18.0%
  • Green

    Votes: 129 28.3%
  • Blue

    Votes: 147 32.2%
  • White

    Votes: 31 6.8%
  • Yellow

    Votes: 11 2.4%
  • Orange

    Votes: 30 6.6%
  • Violet

    Votes: 9 2.0%
  • Purple

    Votes: 17 3.7%

  • Total voters
    456
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what is the diff between purple and violet?

This is a good question - and one over which I have had many arguments.
Purple to me is a combination of red and blue light. I.E. a hole in the middle of the spectrum, no green. Violet is a wavelength shorter than blue. Newton called it Indigo. It can be seen below blue on the rainbow, the shortest wavelength we see.

I am not sure, however, how the eye distinguishes it from blue. It seems that the red cones in the eye are also a bit sensitive to blue, so it may be that cross talk that looks blue to us. Some digital cameras and displays have a hard time with true violet, it comes out blue. Violet is often faked with purple (magenta.)
More than you wanted to know, I'm sure.

As for red being a good color for nigh vision, this is quite true. Used in aircraft cockpits, for example. Look up "Rhodopsin" to learn why.
 
Hey what do you call an LED that only has two pins but does two colours?


I want to replace the LED in my Jolida passive but I can't figure out how to find it on digikey. It glows red when off and blue when on. The symbols on the pcb make me think the current is reversed to make it change colour?
 

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This is a good question - and one over which I have had many arguments.
Purple to me is a combination of red and blue light. I.E. a hole in the middle of the spectrum, no green. Violet is a wavelength shorter than blue. Newton called it Indigo. It can be seen below blue on the rainbow, the shortest wavelength we see.

I am not sure, however, how the eye distinguishes it from blue. It seems that the red cones in the eye are also a bit sensitive to blue, so it may be that cross talk that looks blue to us. Some digital cameras and displays have a hard time with true violet, it comes out blue. Violet is often faked with purple (magenta.)
More than you wanted to know, I'm sure.

There are 7 color names in Russian language: Red, Orange, Yellow, Green, 2 different colors of Blue with different names, and Violet.

By the way, in Eskimo language there are 40 (!) names for the snow, and they can easily tell one from another.

As for red being a good color for nigh vision, this is quite true. Used in aircraft cockpits, for example. Look up "Rhodopsin" to learn why.

Accommodation after red light happens faster. Astronomers use red flashlights as well.
 
There are 7 color names in Russian language: Red, Orange, Yellow, Green, 2 different colors of Blue with different names, and Violet.

Yes, the names your language gives to color influences the way you see them. What are the 2 names for blue in Russian and how would you define them?
By the way, in Eskimo language there are 40 (!) names for the snow
Unfortunately, this is an urban myth.
 
Violet is a wavelength shorter than blue. Newton called it Indigo. It can be seen below blue on the rainbow, the shortest wavelength we see. I am not sure, however, how the eye distinguishes it from blue.

The rainbow colours are conventionally named: Violet, Indigo, Blue, Green, etc.
So the first three are three distinct colors.

People who are aphakic (i.e., have no natural lens in the eye) due to cataract surgery can see further into the violet part of the spectrum. The retina is sensitive to near ultra-violet, but normally the lens filters it out.
(To me, a room 'lit' by ultra-violet black tubes - which apparently appears dark to most people - is as brightly lit as if conventional fluorescent tubes were used.)
 
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the eye distinguishes it because the red receptors have a small sensitivity peak as well there; thus leading to a purple violet tinge ;p

(yes i know it is going around in circles, because colors are ineffible ;p)

it was found while studying intelligence photos of enemy bases, that having a
colorblind person on the team, leads to a higher detection rate, as some colorblind people often can discern different mixtures of colors which seem equal to regular people. and also often rendering for instance camouflage ineffective

afaik.

*edit: the perception of red, to be precise.
 
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Yes, the names your language gives to color influences the way you see them. What are the 2 names for blue in Russian and how would you define them?

As usual. 2 different colors, with 2 different frequencies. They are not of the same frequency with different intensities, they are different colors.
In English people confuse Blue, Indigo, and Violet. Some say that Indigo is a dark blue, some say that Indigo is a Violet.

By the way, paints have more of frequency gradations, with own names.
 
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