On desktop PCs, Depending upon the Motherboard manufacturer and model series, it could either mean nothing other than some gaming marketing jargon or…

When a motherboard has both red and blue ports, the Red ones could be those connected directly to the CPU lanes for USB, with the blue ones being routed through the PCH.
If there is just one red coloured USB A port, it might be designated for BIOS updates (unless they have another colour for that).