There is no reason why changing a router will improve performance, as far as ‘red’ leads , for a while , to make FTTP idiot proof they supplied an regular Ethernet cable with red ends and the port to plug it into was also red on the router ….that isn’t necessary anymore, the colour is irrelevant.
If you have been migrated to DV ( or are about to be ) so need a SH2 router instead of whatever router you had ( because it doesn’t the old one doesn’t have a phone port ) the original mains lead can be reused with the SH2 , basically its a simply replacement , unplug the old router , connect the new in the same place using the same cables
