Red
The colour helps indicate urgency, but exact behaviour can vary by manufacturer.
Dashboard Warning Light
Door Open
Door/boot/bonnet not closed. The usual first step is: Close properly.
Stop safely
Use this as a quick triage label before confirming in your owner manual.
Close properly
Check the matching manual page for your exact brand, model and year when possible.
What it usually means
Door/boot/bonnet not closed.
What to do next
Close properly. If the vehicle feels unsafe, stop in a safe place and arrange professional inspection.