As soon as I get a chance, I will track it down for you. It may not be until tomorrow: I have a pretty full plate this evening.
--------------- Added [DATE]1406745927[/DATE] at [TIME]1406745927[/TIME] ---------------
So like I thought, it is one of the parameters that is sent to facebook. So you cannot style it any further through a direct method. It would be possible to style it through the DOM, after the page loads, but I have not given that a try -- as of yet.
Modify template: facebook_likebutton
Find:
Code:
colorscheme="light"
Replace:
Anyway, this should get you going.