According to the RBG Color Theory, red, green, and blue are the primary stimuli for human color perception and are the primary additive colors. The combination of red, green, and blue in full intensit

According to the RBG Color Theory, red, green, and blue are the primary stimuli for human color perception and are the primary additive colors. The combination of red, green, and blue in full intensity makes white. White light is created when all colors of the EM spectrum converge in full intensity (255 on the scale of 0-255). Conversely, black is demonstrated as a total lack of the additive colors, or 0 on the scale of 0-255. Such theory is largely used by computer scientists to simulate colors in modern computers.

Each of the three primary colors is assigned a range of integral values: from 0 to 255. In other word, each primary color has 256 different intensities. Every time when there is a need to create a color, one value of each primary color will be picked to the color pallet. For example, rgb(27,149,251) means the intensity of the color red on a scale of 0-255 is 27, 149 green, and 251 blue are displayed to make a color. With such implementation, all modern video cards, which are capable of at 16M colors (2563).

In a Bitmap image, anyone can choose two consecutive color code combination, as shown below, to write on and fill a rectangular area. Since the color of pen and background are so close in their values (only the value of red has slight differences: 32 and 33. The color of pen and background are nearly identical. However, nearly is not absolutely. By simply changing the background color to another color, the hidden message will be displayed.