Which elements would you like to change from red? If you’d like to change the background colour of the left sidebar menu, try:
.main-navigation li a {
background-color: #bb00bb;
}
You can use any colour code you’d like and place this code in the custom CSS editor I see you’re already using here: sunnyinkabul.com
You can use a browser inspector like the ones built into Chrome or Firefox to help you find any other elements you’d like to change.
Here are some very helpful posts that will help you customize your site with CSS:
https://dailypost.wordpress.com/2013/07/25/css-selectors/
http://dailypost.wordpress.com/2013/06/21/css-intro/
http://dailypost.wordpress.com/2013/08/29/css-matched-rule-pane/
http://en.support.wordpress.com/custom-design/how-to-find-your-themes-css/
Give those a read and if you need help changing the colour of any specific element afterwards, feel free to post back here.
