the 3 Primary the 3 Secondary and the 6 Tertiary Colors

Perhaps you have learned in school that the three primary colors are red, yellow and blue. Actually that was based on a system that goes back centuries and even to this day, artists still use these as their primary colors. However, in the 20th century, color theory was examined scientifically and the primary colors are now known to be red, green (actually lime or electric green) and blue because their wavelengths are spread more evenly across the visible light spectrum.
Pictured above is a graphic displaying red, lime and blue as the 3 primary colors (along with their HTML hexadecimal codes). These are called additive primary colors because they are the primary colors of light which explains why mixing any combination of these will always produce a brighter color. Because these are the primary colors of light, these 3 colors are used for televisions and computer monitors.

Incidentally, in HTML, colors are displayed by using 6 digit hexadecimal (base 16) numbers. The first 2 digits control how much red to display, the third and fourth digits are the amount of green and the fifth and sixth digits determine the amount of blue to display. Looking at the above graphic, we see the hexadecimal code for red is FF0000. As we stated, the first 2 digits “FF” control the amount of red. Since “FF” is the largest 2 digit hexadecimal number, that means it will display the full amount of red. The green and blue digits are all zero so that means this displayed color will have zero amounts of green and blue. You can see how this holds true by looking at the other 2 hexadecimal color codes.

You probably noticed that mixing these three colors produces three additional colors (called secondary colors):

We now will post another graphic showing these 3 secondary colors, with their HTML hexadecimal codes.

These are called subtractive primary colors because mixing any combination of these will always produce a darker color. These are also known as secondary colors. As a quick example, look at the toner cartridges inside your prtinter. No doubt you saw cartridges for yellow, magenta and cyan (along with a cartridge for black).

You probably noticed that mixing these three subtractive primary colors produces the three additive primary colors:

Now let’s see what happens when we combine the above 2 graphics.

Combining the 3 Primary Colors with the 3 Secondary Colors produces 6 tertiary colors:

The two tables below neatly summarize this web page.

Primary, Secondary and Tertiary Colors
In The Following Order
RED BRIGHT PINK   MAGENTA VIOLET     BLUE     AZURE
CYAN SPRING GREEN GREEN CHARTREUSE YELLOW ORANGE

Primary, Secondary and Tertiary Colors
IN ORDER BY HEX Code    From 0000FF to FFFF00