Secondary Colors
A Secondary Color is a color made by mixing two primary colors in a given color space. Examples include the following:
Additive Secondaries
Light (RGB)
Red + Green = Yellow
Green + Blue = Cyan
Blue + Red = Magenta
Light (RYB)
Red + Yellow = Orange
Yellow + Blue = Green
Blue + Red = Violet
Subtractive Secondaries
Pigment (CMY)
Cyan + Magenta = Blue
Magenta + Yellow = Red
Yellow + Cyan = Green
Traditional Painting Prescripts (RYB)
Red + Yellow = Orange
Yellow + Blue = Green
Blue + Red = Violet
In the RGB color space the colors are added, thus you start with levels of dark colors which are added to produce lighter colors. RYB uses pigments, which are not added, and thus combining colors using the RYB color system will result in a darker color.
Pigment (GVO)
Green + Violet = Blue
Violet + Orange = Red
Orange + Green = Yellow