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Topic: Best high Power RGB Led (Read 1 time) previous topic - next topic


Hi , i am currently using Piranha RGB led s from Sparksfun they work very good but Now , i want a rgb led which can EXACTLY display the color that user selects from color dialog box or if he specifies rgb value

It should not be too expensive and it should definitely be compatible with Arduino

And another thing is that why cant these LEd's display black color (rgb 0,0,0) even though computer can display it , Is there any fix for that ?


To get Exactly the same color is to use exactly the same LED as the screen uses.
Best bet is to have the user map his perceived color to the presented color, and then use software to keep up that mapping.

Black is the absence of all color, yes? So put your RGB LED on a black background - when off, that is as black as it gets.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.


Oct 27, 2012, 07:25 pm Last Edit: Oct 27, 2012, 07:27 pm by Grumpy_Mike Reason: 1
i want a rgb led which can EXACTLY display the color that user selects from color dialog box

Then you are stuffed because it can not be done.

Also note that exact colour and perceived colour are two different things because the perceived colour depends on the background.


See also:-


Aside from the impossibility of displaying the EXACT color as another device/ screen, how would you specify " not too expensive" and particularly " Arduino compatible" ?



What makes you think your monitor is displaying the "exact" color you think it is?  For one thing, they need to be calibrated http://spyder.datacolor.com/

Besides that monitors have a certain colorspace with better monitors able to show more color gamut.  Viewing angle effects the color (much more variation on TN panels than VA or IPS panels). 

If you show the same picture on 2 different uncalibrated monitors, you'll get very different results.

As others have said background color makes a huge difference in perception.  So do viewing conditions.  When calibrating a monitor it factors in ambient light.  When printing pictures for exhibition, my print software compensates for the ambient light the picture is intended to be viewed in.

How do you intend to generate the colors on the LED, run it at full power and PWM it?  That's relying on the performance of the viewers eye to render the color and you're really displaying nothing remotely like the color on the screen even if you manage to get it to look similar.

Even calibrating something as simple as your white balance, getting pure white and pure grey is very hard to do.


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