Yes, it it possible. But it may not be as simple as you think - it may depend on what the file is stored as. A bitmap is easy: a pixel is a pixel. A jpeg is not so easy: the data is compressed using a "lossy" algorithm, so what starts out as a red pixel next to a blue pixel may become a magenta pixel.
Either way, the first place to start is to load your image:
Image i = Image.FromFile(path);
Then look at each pixel individually:
int pixel = i.GetPixel(x, y);
The pixel then contains the ARGB value.
int Red = (pixel >> 16) & 0xFF;
int Green = (pixel >> 8) & 0xFF;
int Blue = pixel & 0xFF;