How to use Blue zone as VLAN via Green?

Hi,
that’s what I tried, but the BLUE zone didn’t show up neither on my virtual machine nor on my IPFire.
However, I configured the BLUE zone and the VLAN via the config files and it works.

I wanted to configure multiple VLANs according to your guide

Unfortunately it seems to be outdated.
Do you have an solution or any hints for a recent system?

Rehards
Pete.