Digium phones and BLF

Using FreePBX 12.0.76.2

Simple question, yet I can't find the answer.

We're using Digium phones (D40, D50 and D70) in the office.

The BLF light up when someone is on the phone.

I want the BLF to also light up with someone is anything else than available.

For example, if someone becomes "busy" I would like the BLF on other phones (which have this extension in speed dial) to like up red.

Thank you!