Anyway to declare "red" = #FF0000, and change it later? [duplicate]

This question already has an answer here:

• How can I define colors as variables in CSS? 19 answers

Right off the bat, I apologize for the confusing question. I'm not sure how to ask it really.

Basically, I want the ability to declare somewhere that "Red" equals a specific hex, so that when designing my website I can call out "Red" instead of that hex code. I then want the ability to change what red equals later on if I don't like it, but without having to go through and change it everywhere on the website. Kind of like including a header, footer or another snippet of code, but with a color.