I am Good at CSS and would want to work on CSS for WPMU Themes. Is there a possibility???

I am Shreyans Gandhi from India.

I have been working on Wordpress for over a year now and have been working as a freelancer, making wordpress websites for people all over the world.

I am really good at CSS and would want to use my skills to develop and enhance WPMU Themes further.

Is there a possibility of this??? How shall I proceed???