Many times when I am working on a customer’s order, they will write a comment like “print warm” or “slightly cooler than guide”.
I want to share one of my favorite quotes.
“What some people call help, I call sabotage.”
Allow me to explain. There are many color models depending on the type of color correcting you are making.

Rather than writing a three page explaination of the various color spaces, please follow this link.

It is a site I found while researching color spaces and does such a good job, I’ll just let you visit them.

Back to the sabotage, the color space used in silver halide based printing is the RGB color space.

“Warm” refers to the red-yellow side of the color wheel while the term “Cool” refers to the cyan-blue side of the color wheel.

Telling the lab you want warm could lead to prints that are more red when what you really wanted was more yellow for that “Golden skin tone”. Another example would be to ask for cooler than proof because you wanted the skin tones to be less yellow, but the lab employee takes out red instead leaving the subject looking dead.

Along this same train of thought, green and magenta can be either warm or cool. If the color is a yellowish-green it is warm and a cyan-green is cool. A reddish magenta is warm while a bluish magenta is cool.

Also, Don’t use vague or made up terms like brightness, chocolatey or peachy. The lab employee may misinterpret your understanding of that term. I once had a customer request “add brightness” when they really wanted contrast. I lightened the image thinking they wanted a change in density.
Summary: If you are wanting specific color corrections made or want a certain look to your prints, please use actual colors that the color person at the lab can use. Red, green, blue, cyan, magenta and yellow are the colors available to them. They can correct saturation (how vivid the colors are), density (overall lightness or darkness), contrast (the difference between highlight and shadow areas), sharpness and gamma (a.k.a. luminescense – kind of like contrast for the colors).