Change Registration Button

Hi,
Love the plugin. Really good and nothing else out there as good.
I was wondering the best approach to change the login/ register/submit button. I have changed the width with custom css, but is there a way with css to alter height, colour, border etc?
If not will it have to be jquery or javascript? If so can you provide me with a relevant link or some advice.
Thanks very much.
Any help would be appreciated hugely.
Theo Cooke

site: miklos.co.uk

(also posted this on your website)

http://wordpress.org/extend/plugins/theme-my-login/