Get colors between two color HEX refs or RGB [duplicate]

Question

Possible Duplicate:
Color Interpolation Between 3 Colors in .NET

I have been trying to get a categories list of colors using C#:

Red:
255, 69, 0
255, 99, 71
etc.. 

Green:
0, 250, 154
143, 188, 139
etc...

So far I have been pretty unsuccessful. Ideally, what I'd like is a way to supply two HEX refs or RGB refs and get a list back of say 10 colors between those two references. Is this possible in C#?

EDIT

Found this... http://meyerweb.com/eric/tools/color-blend/ just converting the js to c# now. Will post when its done.

Answer 1

I am not aware of built-in function which would help you, but you can do it yourself.

As long as color can be defined using 3 numbers (R,G,B), you can take two colors:

(R1,G1,B1)
(R2,G2,B2)

Then divide diff between pairs and produce numbers by intervals.

int numberOfIntervals = 10; //or change to whatever you want.
var interval_R = (R2 - R1) / numberOfIntervals;
var interval_G = (G2 - G1) / numberOfIntervals;
var interval_B = (B2 - B1) / numberOfIntervals;

var current_R = R1;
var current_G = G1;
var current_B = B1;

for (var i = 0; i <= numberOfIntervals; i++)
{
    var color = Color.FromRGB(current_R, current_G, current_B);
    //do something with color.

    //increment.
    current_R += interval_R;
    current_G += interval_G;
    current_B += interval_B;
}

I haven't compiled the code, but you get the idea.

Answer 2

What you are looking for is called interpolation. In this particular scenario you need to interpolate data between two key points.

Since interpolation is a really common scenario when programming, I wrote a generic solution for it, easily allowing you to interpolate between two or more key points, using either linear or even cardinal spline interpolation.

Using my library you could calculate intermediate colors as follows:

var keyPoints = new CumulativeKeyPointCollection<Color, double>(
    new ColorInterpolationProvider() );

keyPoints.Add( Color.FromArgb(0, 250, 154) );
keyPoints.Add( Color.FromArgb(143, 188, 139) );

var linear = new LinearInterpolation<Color, double>( keyPoints ); 

// E.g. to get a color halfway the two other colors.
Color colorHalfway = linear.Interpolate( 0.5 );

You would have to implement ColorInterpolationProvider by extending from AbstractInterpolationProvider<Color, double>, but this is quite straightforward, and more information can be found in my blog post.

This example uses the Media.Color class, but you could just as well support any other Color class by passing along a different interpolation provider.