35th wedding anniv is represented by coral so that might give you some ideas?
A nice present is to make up a photo album charting important milestones in peoples lives eg photos of them as babies, graduating, their wedding, first house, children and grandchildren, pets etc. You can also include birth certificates etc to add to the photos.
The nice thing about making an album for someone is the personal thought and effort that goes into it - also, the album could be coral coloured which covers the 35 theme?