GDI+: Set all pixels to given color while retaining existing alpha value

Question

What is the best way to set the RGB components of every pixel in a System.Drawing.Bitmap to a single, solid color? If possible, I'd like to avoid manually looping through each pixel to do this.

Note: I want to keep the same alpha component from the original bitmap. I only want to change the RGB values.

I looked into using a ColorMatrix or ColorMap, but I couldn't find any way to set all pixels to a specific given color with either approach.

Answer 1

Yes, use a ColorMatrix. It ought to look like this:

  0  0  0  0  0
  0  0  0  0  0
  0  0  0  0  0 
  0  0  0  1  0 
  R  G  B  0  1

Where R, G and B are the scaled color values of the replacement color (divide by 255.0f)