It may sound strange, but the human eye can only sense three colors, blue(B), green(G) and red(R), but through a balanced mixture of these three colors, we are able to see all colors. The three colors are known as the additive primary colors, and they produce a white color when blended in equal amounts.
All colors can also be produced through a mixture of yellow(Y), magenta(M) and cyan(C). These three colors produce a black color when blended in equal amounts.
They are known as the subtractive primary colors, and they form a complementary color relationship with B, G and R, respectively (opposite colors, or negatives).

Composition of Color Negative Film
The above figure shows a conceptual diagram of the moment a subject is recorded on color film. Light from the multi-colored subject passes through three layers of light-sensitive material on the film: the top layer is sensitive only to the B part of the subject, the next layer is sensitive only to G, while the third layer is sensitive only to R. When the film is developed, their respective complementary colors of Y, M and C are produced. This is the color negative.

Composition of Color Prints
A color negative, therefore, does not give us true color representation. Further work is required before we can fully admire our photograph.
The conceptual diagram shows the moment that the subject's image is produced on a color print. When light passes through the color negative and on to the color print, three light-sensitive layers on the print work in a similar way to layers on the color film. Thus, when the print is developed, the complementary colors of the complementary colors in the negative are produced. This gives a positive image.