Spice up existing wall decor
So you have in-game wall art that for some reason doesn't fit your taste: the size is awkward, the colour doesn't fit the interior or it's a store item and you'd like to keep your lot strictly store content-free?
To "resize" existing wall decor, photograph smaller sections of it to give it a new life.
http://imageshack.us/a/img13/4547/screenshot38wp.jpg "width=640" "height=480"
If you're not happy with the colour of a particular art piece but would really like to use it, try aiming some coloured light at it to adjust the colour, then take a photograph of it.
http://imageshack.us/a/img812/7863/screenshot41c.jpg "width=640" "height=480"
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http://imageshack.us/a/img692/2956/screenshot40zn.jpg "width=640" "height=480"