The color of the network page denotes the network cabling in the physical world.
RED = Remote , IPMI, iLO, iDRAC, etc. YELLOW = control, All network traffic related to mysql, keystone, rabbitmq, etc. lives here. GREEN = vmnet, All network traffic related to vm's communicating with each other / internet lives here. BLUE = storage, All network traffic related to storage (nfs / iscsi / etc.) lives here. WHITE = backup, All network related traffic related to making storage backups live here.
White is currently not yet implemented due to a lack of hardware within Linuxfriendly.