Customized Style.css

Great theme! Thank you for your great work! 🙂
I’m hoping you are able to help…I’m having a bit of difficulty making changes to the css. I am changing the background (no problem) and the color scheme however when I make the changes in the style.css file they don’t seem to “take”. I’ve been attempting to edit the color for the blog menu hover, title hover, blog title hover, and blog hover, and widget colors. Sorry I know that sounds like a lot, I essentially just want to be able to change the color scheme all around but seem to be having difficulty with the css file. Any advice?