Color management tab vs. Color Space Transform tool

Hello!

In Color page: What's the difference between Color management tab in settings vs. Color Space Transform tool?
As far as I understand, you should always set your color space before doing any work in Color page?

Thank you!

One is a group of Project Settings, one is an effect you can use on a per-clip basis.

According to Alexis van Hurkman, the math behind it is the same, BTW.