Need to use different background colors for all my social media categories

I already ask this question so many times, http://designwall.com/question/how-to-change-the-color-for-category-tags-above-the-post/
but i think have asked wrong question. So we can’t solve the problem. This time i let my deveoper ask instead so he can be more get to the point than me
This is what we need actually.
“I am using buttons links to my category tags like facebook, twitter, google plus, swarm etc…. all those are category which I use in my website at http://socialmediamarketing.tips/
My question is I want to use different background colors to my all categories buttons links. For example to facebook I need to use facebook blue color, to twitter need to use twitter color, to google plus need to use same google plus colors etc…. for all buttons I need to use different colors. Please let me know what css I need to write there?”