That will probably be so that they can be used in a traffic or automotive 
application. You can make orange from green and red, but a failure results 
in a red or a green where an orange should be. ie. It doesn't fail safe (see 
earlier thread).  Traffic lights are the obvious one. It's pretty tightly regulated 
for roadage signs as well as the colour infers the importance.

Steve.
 

On 27 Nov 2006 at 11:03, Mike Hord wrote:

> I just bought some LEDs from Digikey/Mouser for a color mixing
> project I'm thinking of playing around with (why paint when you
> can light?), but I'm a little confused by the fact that the "matched"
> LEDs I bought come in FOUR colors: RGB and orange.
> 
> This is new to me, and you-know-whoogle doesn't have anything
> to offer.
> 
> I accidentally bought GBO in my first order, so I picked up some
> red ones from Mouser (same manufacturer part number, but
> Mouser doesn't have a minimum order)(I prefer Digikey due to
> proximity).  I have all four- am I "supposed" to use them all?
> 
> Mike H.
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==========================================
Steve Baldwin                          Electronic Product Design
TLA Microsystems Ltd             Microcontroller Specialists
PO Box 15-680, New Lynn                http://www.tla.co.nz
Auckland, New Zealand                     ph  +64 9 820-2221
email: steve@tla.co.nz                      fax +64 9 820-1929
=========================================


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