Questions about how to use prototypes

[sfpiano]

1)

Color.prototype.fade = function() {
	trace("asdf");
}

this.onEnterFrame = function() {
	var col:Color;
	col.fade();
}

I have this code in the first frame of my movie. When I try running it, I get the following error:

**Error** Scene=Scene 1, layer=Layer 1, frame=1:Line 16: There is no method with the name 'fade'.
col.fade();

2) Is it possible to have prototype functions defined in a seperate .as file and then imported/included into the main program? I've tried doing this a couple of times and I wither get a compilation error or the function doesn't get called when I try to use it.

[a_modified_dog]

say you have a movieclip on stage, a yellow circle with instance name - ball
using this code, you can change the color to red

Color.prototype.setTint = function (r, g, b, amount) { 
 var trans = new Object (); 
 trans.ra = trans.ga = trans.ba = 100 - amount; 
 var ratio = amount / 100; 
 trans.rb = r * ratio; 
 trans.gb = g * ratio; 
 trans.bb = b * ratio; 
 this.setTransform (trans); 
}; 

myColor = new Color (_root.ball); 
myColor.setTint (255, 0, 0, 100);

you can cut the code into a tint.as file and load it with -

// Flash -
#include "tint.as"

//tint.as -
Color.prototype.setTint = function (r, g, b, amount) { 
 var trans = new Object (); 
 trans.ra = trans.ga = trans.ba = 100 - amount; 
 var ratio = amount / 100; 
 trans.rb = r * ratio; 
 trans.gb = g * ratio; 
 trans.bb = b * ratio; 
 this.setTransform (trans); 
}; 


function applyTintOverTime (r, g, b, amount, steps) { 
 var counter = 0; 
 var increase = amount / steps; 
 amount = increase; 
 _root.onEnterFrame = function () { 
  if (counter >= steps) { 
   delete this.onEnterFrame; 
  } else { 
   myColor.setTint (r, g, b, increase); 
   increase += amount; 
   counter++; 
  } 
 }; 

} 


myColor = new Color (_root.ball); 
applyTintOverTime (255, 0, 255, 100, 20); 
// the first three numbers are RGB values, 
// then tint value, then no. of frames

this will fade the color gradually

hth