In the text-based programming, such as xBase (dBase / FoxPro / Clipper), RGB color is defined by very simple as the basic command SET COLOR TO RGB color. In xBase programming, the color code used is R (red / red), G (Green / green), B (blue / blue), W (white / white), and N (none / no black). In the context of the RGB or color of light, then it is actually not black. The black color is the color without light, so the black color RGB value is zero.

example:
RGB (255,0,0) will produce a perfect red color
RGB (255,0,255) will produce a violet color (in RGB, but it would be close to pink)
RGB (0,50,0) will produce a dark green color
In hexadecimal, the method of determining the same color, eg red color with the RGB (FF, 00,00), blue color with the RGB (00,00, FF). Giving the maximum RGB values, ie RGB (255,255,255) or RGB (FF, FF, FF) will produce a white color. Instead giving a minimum value of RGB (0,0,0) will produce a black color.
To produce a gray color can give the same value on the elements of R, G, and B. If the value is small then it will produce a dark gray and the greater its value will produce a gray color even brighter. For example RGB (20,20,20) produces a dark gray and RGB (200,200,200) will produce a gray color lighter.