CSS: different backround and body color with shadow

[Puriom]

Hello!
In default theme, I'd like to have two different colors. Now both are white - I'd like to have the background p.e. red  and the body yellow (just as an example, like the photo attached), and the body to have grey shadow at the meeting point with the red background.
Also (if I don't ask too much) what if I'd like to add a photo instead of red color?
Could any member tell me what could I add and to which css file?
Thanks n advance

PS. The thing I do not know is which value is for body and which for background.


Here (http://www.prestashop.com/forums/topic/252693-change-theme-or-at-least-background-color/) I found out about the colors, but I don't know about the image, and the shadow.)

Edited June 21, 2014 by Puriom (see edit history)

[Cooltights]

Hallo

 

I am pretty sure you want to find the "global.css" file and put the background image in.

 

I have done something similar to my shop with a background image

 

You can see it here: By Moxy tights

 

They grey area in the top is from an image, in the start the entire area under, with the black was also from an image. But now it's just an black background-color: and then i added the background-image: for the grey top

[Puriom]

Thanks Cooltighs!

Could you copy paste here the modification, please?
Also, any idea about the two different colors?