UBB.threads PHP Forum Software Community Forums Resources and Customizing How Do I? Some newbie questions

Ok i am getting there i think
A couple things though would like to chafe the color to dark green for the headers and a really light beige for the background how do i do this i could not figure out how to edit the styles

Also want to put my logo on a header on top of the page how do i do this ?

I am by no means a computer guy