In the Advanced tab from Design | Template Designer, you can easily edit and customize the fonts and colors of your blog without any knowledge of HTML or CSS.
How to edit the colors in your blog?
First choose the element you would like to change the color of. Then choose the color you would like that element to be. You can either click on the color you want or enter your own color hex code. There are two other options for your better choice by choosing "Colors from this template" and "Suggested colors" provided by Blogger.
When you change your blog colors, you can view your changes in the blog preview beneath the Advanced panel. Click on "Expand preview" to open it higher. Make sure you save your changes after you have finished selecting the colors for your blog by licking APPLY TO BLOG button in the right corner above your screen. If you don't like your changes, you can revert back to your default colors by clicking "Clear advanced changes to..."
How to edit the fonts in your blog?
First choose the element you would like to change the font of. Then choose the font you would like that element to be by clicking the radio button next to your font of choice. You can also change the font style to bold and/or italic by checking the box next to the style you want and you can make the font size larger or smaller by choosing a size from the font size box.
When you change your blog's fonts, you can view your changes in the blog preview at the bottom half of the screen. Make sure you save your changes after you have finished selecting the fonts for your blog by licking APPLY TO BLOG.