ply is your player object.
v is the player object of the player you are sending the message to.
The reason your code isn't working is because you still need to separate each parameter of tsaycolor with commas.
ULib.tsayColor(nil, Color( 204, 204, 0 ), "[FADW-Admin] ", Color( 255, 255, 255 ), ply:Nick(), Color( 100, 255, 200 ), " has joined the game!")