Software to play around with render colour schemes on house

[sjtgeray]

Any suggestions please for PC or iPad software that i can use with either a photo or scan of the original architect drawings of the front of the house that will allow me to play around with render colours and cladding boards?
Currently the house is brick but SWMBO wishes to "update" the look (which has merit as extension to front was done with different colour bricks)

I remember Dulux had something for internal rooms but that was years ago.

Am reasonably PC literate and once did some stuff with a "borrowed" copy of Autocad, though it was so long ago i think it ran on DOS !!