does anyone know if you can still buy 35mm film for cameras that gives a similar colour to that used in the 1970's? a sort of warm, washed out colour? any ideas would be appreciated.
Are you sure it's the film that gave that effect? Ask at your local photography shop about filter systems (eg Cokin) - these are squares of plastic placed in front of the lens to give different effects - misty, moody, star bursts, colours.
While there are various types of film which will effect the appearance of a print, this is most often done using as Famous5 suggests, filters in front of the lens or even processes during development.
I suggest you ask for a CD when having prints developed, then by using good photo software you can manipulate the colour to exactly what you want. The 1970s prints you refer to have deteriorated with age.
May I suggest that you get yourself a poloroid, take a photo, leave it on the windowsill in the sun for a couple of weeks and then you'll have what you want.