Seperate Widget Color Background / Title

Hello,

It might have already been posted somewhere around here, but I cannot seem to get it to work for my theme. Im currently trying to customize my widgets area. I would like to show different colors for certain type of widget areas. Below is an example of how I would like it to look like, with different colors of course. But I was wondering how I could achieve something like this and where I should put the codes in my css files. I would really appreciate your help.

example: https://s21.postimg.org/65p0c1ixz/widgetbar.png

my website: https://www.iphonerz.com/product-category/iphone-accessories/iphone-5/cases-iphone-5/

thanks