New Theme

Hi
I am using Crayon for highlighting linux commands on my site. I want to highlight certain paragraphs in a different colour to make them stand out for readers to take note of them. I have tried creating a new theme but the plugin doesnt make it available for you to use, rather it requires you to submit it to the developer for use globally. Is there a way to create custom themes/colourings for your own site?

If not, are there any other plugins which I could use for highlighting a paragraph of text?