It's bullshit and fake news lah.. Yellow means cannot go to enclosed places like malls etc. You can go anywhere that is open, including going home. Red means you will need to be quarantine - either at home or at centralised facilities if you don't want the entire household to be quarantine as well.
Yellow means you've been to a mid-high risk area. Red means you're either positive or have been in close contact with a positive person.