• Create an SNMP Interface on a host 
• make sure its not working with snmp 
• add a template for snmp monitoring like "Generic by SNMP"
• SNMP interface will be green
• go to item  "Uptime hardware"
• disable it 
• interface will turn grey

This is due to the preprocessing step custom on fail that sets any error to value 0

zabbix get an item with a value populated in this case and tells the SNMP item is working and turns the interface green

expected grey / red it shouldnt look at the preprocessing steps or not rely on custom on fail