Hot Pixels: A hot pixel is a permanently lit white pixel is called a glowing pixel. Hot pixels are most commonly seen against a dark background.
Dead Pixels: A dead pixel is a defective pixel that remains unlit. Dead pixels are most commonly seen against a white background.
Stuck Pixels: A stuck pixel is most commonly seen against a black background. Stuck pixels can be seen in the colors of red, green, blue, cyan, yellow, or magenta. The most common of stuck pixels are red, green, or blue pixels. "Each pixel on an LCD monitor is composed of three sub-pixels (one red, one green, and one blue) which produce the visible color of the pixel by their relative brightness. A stuck pixel results from a manufacturing defect, which leaves one or more of these sub-pixels permanently turned on or off."
"Stuck pixels are not guaranteed to be correctable, and can remain faulty for the life of the monitor, however might be fixed by flashing numerous colors with a very rapid intensity."
Quote source: http://en.wikipedia.org/wiki/Dead_pixel
The reason I have brought this issue up is because my Nikon D80 is currently experiencing stuck pixels. There are two spots on certain photos, usually night photographs with dark skies or a dark background that appear in the colors of blue, green, or red. So if you find that there are a few little spots appearing in your photos after you shoot them, zoom in and see just what it is. It maybe possible that it could be dust from your lens, but if it is showing up in the form of colors then you maybe experiencing a pixel problem.
Below are two examples of photos that I shot. Both have STUCK PIXELS. Photos were shot with the ISO set to 400 and roughly 8 second exposures.
I do not currently know of any way to remove this issue except replacing the sensor. For LCD screens there are ways you can remove the three types of Pixel Problems I have mentioned. I hope this isn't an issue any of you suffer from. It can be very irritating to have to remove spots from your photos.