std pressure efis button on 737

Hican I check something here with you guys please.On the 737, when I see STD in yellow ( or is it green I am colour blind, but don't tell the airline ;-)) it still shows the HPA value in white, does this mean that I am STD mode with 1024 standing by for when I decend below transition level ??Also - on climb the HPA value in white, becomes yellow/green with a box around it, I think this happens at transition alt, but does it mean that the system has made the switch to STD or is it waiting for me to hot the switch to STD ?MTIASteve