pidgin buddy list font size / chat messages color

[mattoukn]

hi,
i searched like everywhere but i cannot find any information on how to 
change the size and color
of my buddies in the buddy list.
i am using a gtk+ theme and i would like to change the color of the 
names from grey to black
and increase their size as well because they are really hard to read.
i also cannot change the color of the text in a chat window. i can 
change everything there but the messages themselves stay in the same 
grey like my buddy list names (here i can change the size though).
i think as an expert these questions should be easy to answer, so thanks 
in advance.
best regards