questions from the girlfriend

1. The passport picture, does the background need to be a certain colour?
2. If we use the VIP service is the passport photos included in this service?

When she goes to a photo services/photo printing shop, have your fiancée tell the staff she needs passport photos for UK visa (I believe it is also the same for Schengen visa). The background should be plain cream or light grey in colour if I remember correctly.

I think if we choose vip service they will do the photos for us

If you'r not sure then take photos.

Here are UKVI Rules for passport photos
https://www.gov.uk/photos-for-passports

We used the VIP service but we took our own photographs - and I suggest that you do too for peace of mind. Just take a copy of the rules above to your local photo shop and ensure that the UK style passport photographs abide by those specifications exactly.