$3\mathrm{.}21$ LAB: Remove gray from RGB

Summary: Given integer values for red, green, and blue, subtract the gray from each value.

Computers represent color by combining the sub$-$colors red, green, and blue $($rgb$).$ Each sub$-$color's value can range from $0$ to $255.$ Thus $(255,0,0)$ is bright red, $(130,0,130)$ is a medium purple, $(0,0,0)$ is black, $(255,255,255)$ is white, and $(40,40,40)$ is a dark gray. $,130$ is a faded purple, due to the $(50,50,50)$ gray part. $($In other words, equal amounts of red, green, blue yield gray$).$

Given values for red, green, and blue, remove the gray part.

Ex: If the input is:

$130,50,130$

the output is:

$80,0,80$

Find the smallest value, and then subtract it from all three values, thus removing the gray.