what do the colors of a usb port mean
I have a T420S and I changed the BIOS setting Config--> USB-->'Always ON USB Charge in Off Mode' to 'Enabled'. After this, when I connect my smart phone on the yellow USB port (laptop powered off), it charges but, requires the laptop to be connected to power source (charging adapter). Is there a way to charge the smart phone on yellow USB port even when the laptop is not connected to a power source?