That means two things: you need extra utitilies to have different reds or, you don't mind to adjust the same red that will impact in the rest of the website. As a designer I do this all the time. If my design is complex to the point I would need several reds, then i would use a different value in the class name, like numbers or other options.

Then my workflow for that case would be: create the new color value, compile the CSS, change the class name in those places where I want to use the new red.