I'm from one of the colleges, but I am trying to get my friend(who's not in a college) to shoot with me. I noted at a previous match that photographers were allowed onto the pitch(two students and two in casual clothing).
For school related events:
1. Ask the school for permission to be a photographer.
2. If you're a former student of the particular school and if there's a teacher you know there, it's easier to request to be a photographer.
3. They may ask you to send them a copy of the photos.
For S.league or international matches:
1. You are not allowed to take photos on the sidelines of the pitch. (unless you have a press pass or the authorised photographer.)
2. Taking photos from the stands or gallery is allowed but it's for own use. (unless there is a related competition held)
3. The security have right to stop you from photography. (if there are rules and regulation for photography)
NOTE: For such events, it's better to seek clarification from Football Association of Singapore (FAS) or the Singapore Sports Council.
A divs usually if you can enter the compound (just tell the guard u're there for the match), and you're ok to shoot. however, for the finals (which will most prob be held at Jalan Besar stadium, you'll need a pass for that.