Your variable names represent a value, not a color. You should ask yourself what the function of that value is before naming the variable.
But that's just me. CSS is not something you can let slide. Adding templates, widgets, and pages on a mass scale (20+ templates, 30+ widgets, 500+ pages), your CSS deficiencies will show quickly.
Thanks for being patient with me while I explore alternative solutions.
We both know CSS. But we use them entirely differently.
On a site with 500+ pages, by the time you've implemented all of your !blue to !green, or !light_orange to !dark_orange throughout your stylesheets, management will be considering another redesign.
I find that for simpler sites, naming colors after their closest tone works well, but when I have a dozen shades of the same color, I start to run out of names very quickly (e.g. it's not unusual for me for a single page to have different background boxes, zebra striped tables, subheaders, selected/hover states and an array of other details on top of the overall layout)