Display each category name with a special colour on the header

Hello,

I am writing for the first time on this website but I am using it almost every day. Thanks to everybody for this good sharing.

There is my concern:
I have created an header which display category name /or page title, depend on the context.
I would like to stylise each category with one colour
Is someone have an idea to how to proceed?

This is my website and the code is under:
<?php bloginfo('name'); ?><span style="color:#8BC53F;text-transform: uppercase;font-weight:normal;"><?php single_cat_title(); ?><?php if (is_single()){the_category(', '); }?></span><span style="color:#0071BC;text-transform: uppercase;font-weight:normal;"><?php if (is_page()){the_title(); }?></span>

Thanks very much