Dynamically change color to lighter or darker by percentage CSS (Javascript)

Question

We have a big application on the site and we have a few links which are, let\'s say blue color like the blue links on this site. Now I want to make some other links, but wit

Answer 1

There is "opacity" which will make the background shine through:

opacity: 0.5;

but I'm not sure this is what you mean. Define "reduce color": Make transparent? Or add white?