thanks, great info here.
I had no idea that there were colors that you coudn't do with a LED, brown, of course, never thought about a brown led... I want to ask why but I'm going to look for it. 
I know that it's almost impossible to get GOLD on a monitor, but I've seen some quite good goldens.
Anyway, I'm trying to do the thing with pots, I've been trying for hours and no luck, the analog pins that I try to read return a lot of noise, specially on the pot that controls de red led.
Here's the circuit
I tried a few variations, a 10k resistor from pot to GRD instead of a direct link, a capacitor between the 0% and 100% pins... Nothing, I must be doing something fundamentally wrong.
And here's the code.
int potR=A0, potG=A1, potB=A2;
int potRval=0, potGval=0, potBval=0;
int Rv=0, Gv=0, Bv=0;
int lastRv=0, lastGv=0, lastBv=0;
char s[16];
int redPin = 9;
int grnPin = 10;
int bluPin = 11;
int redVal = 0;
int grnVal = 0;
int bluVal = 0;
void setup()
{
pinMode(redPin, OUTPUT);
pinMode(grnPin, OUTPUT);
pinMode(bluPin, OUTPUT);
Serial.begin(9600);
}
void loop()
{
potRval=analogRead(potR);
Rv=map(potRval,0,1024,0,256);
//delay(5);
potGval=analogRead(potG);
Gv=map(potGval,0,1024,0,256);
// delay(5);
potBval=analogRead(potB);
Bv=map(potBval,0,1024,0,256);
// delay(5);
if(Rv != lastRv)
{
lastRv=Rv;
analogWrite(redPin, Rv);
}
if(Gv != lastGv)
{
lastGv=Gv;
analogWrite(grnPin, Gv);
}
if(Bv != lastBv)
{
lastBv=Bv;
analogWrite(bluPin, Bv);
}
sprintf(s,"%d,%d,%d",Rv,Gv,Bv);
Serial.println(s);
}
The green and blue are more or less ok, there are ranges where they flicker a bit but probably that's normal.
But the red one is giving me nightmares.
Not only it flickers a lot at low values, the red pot somehow affects the other pots.
With all pots to the left, I have values 0,0,0, with all the pots to the right I have 255, 255, 255.
I start to turn the red pot to the right, at some point the values from the other pots start to get affected, for example
167,5,5
167,5,5
167,6,0
165,0,0
167,5,5
167,14,5
167,5,6
165,0,0
165,5,5
167,5,5
167,5,5
167,0,0
165,0,5
167,5,5
167,5,5
167,6,0
165,0,0
167,5,5
167,13,5
167,5,6
And this keeps changing without me touching anything.
It's quite interesting to use the Serial Plotter in the Arduino IDE, but the fact is that I have no idea about what I'm doing wrong.
Another strange thing, with the serial output reporting a consisten 6, 0, 0 I see flashes of blue and green, it looks that somehow the red current leaks to the other colors... I tried another led (some batch, same seller) and it do the same thing.
so I make sure that I never analogWrite values over 128.
