How to change the text color with LaTex

[mcastillo356]

TL;DR

I want to edit and introduce color, to correct a misleading detail

Isn't it $$\color{red}x\color{black}y$$

 

[phinds]

how about xy

 

[robphy]

Rather than define the colors of the highlighted text and then respecify the normal colors of the original text [which can be tedious]
as you did in

\color{red}x\color{black}y

use braces around the highlighted text to change that to the highlighted color.

\color{red}{(x+1)} y

$\color{red}{(x+1)} y$

or to be fancy
$\color{red}{ \stackrel{\rm incorrect} {(x+1)}} y$
(right-click to see the code)