A message that says that when you go into a National Rail train or a Starbucks café you can feel safe.
But is that message backed up by anything concrete? In a different comment thread here, I linked to a local initiative called Emergency Entrance where this is backed up by an action plan that participating venues need to adapt at a shop level and carry out at any time of the year.
I even saw a float from the Premier League in Brighton and we know how much work is still needed there.
That goes against your thesis though. It's an example of a well-known organisation that did not do nearly enough work to be considered safe, and yet it can very easily adopt the colours without any tangible commitments.
I understand that maybe corporate participation in Pride sends such a message of safety. But if that message isn't backed up by concrete actions to offer actual safety, that can even be dangerous.