Yeelight Tasker Variables

Does anyone can explain me how it works the yeelight tasker variables? I mean what can I do when I get %YeelightColor, CT_VARIABLE %YeelightCt, BRIGHT_VARIABLE %YeelightBright, I mean I understand I can retreive it but then I want to set the parameter. Mi intention is to put a random color using %YeelightColor using a gesture of miband 4, I already use %gesture_count from mibandTools.

Thanks in Advance