A communication device that forms a first Basic Service Set (BSS) communicates a radio frame including a preamble and a data field of a physical layer (PHY). The preamble includes an Extremely High Throughput (EHT) Signal Field (EHT-SIG-A). The EHT-SIG-A includes a subfield for setting a BSS color, and if the communication device and a first other communication device are to cooperatively transmit the radio frame to a second other communication device, a value of this subfield is set, without changing the BSS color used in a first BSS, based on the BSS color of a second BSS to which the second other communication device belongs.