How to make a Wordpress theme with a fully customizable site title?

In the Modernist Wordpress Theme the user can change the colour of the site title (in the Modernist theme it is the link inside h1).

You can even replace that text with a image开发者_JAVA百科.

I'm building a Wordpress theme form scratch and I would like to know how to build a Wordpress theme so that the user can change the colour of the site title and have to option to replace it for an image (e.g. png logo) using the dashboard.

Wordpress 3.0 supports custom headers http://codex.wordpress.org/Function_Reference/add_custom_image_header

Other features can be added with theme options page, good totorial how to make this page is here http://forthelose.org/how-to-create-a-theme-options-page-for-your-wordpress-theme