RGB defines color using three light primaries; R for red, G for green and B for blue.
Each primary is given a double digit hexadecimal (0-9,A-F) value; (F=15 decimal and
FF=255 decimal). Each color is defined by combining the three primary values in RGB order. For instance: red=FF0000, yellow=FFFF00, blue=0000FF, a gray=A7A7A7 or 3E3E3E, black=000000 and white=FFFFFF.