[RyDeR`]

You forgot to add a ',', but you don't need format at all:

pawn Code:

dcmd_say(playerid,params[]) 
{
    if(IsPlayerCommandLevel(playerid, "say"))
    {
        if(!strlen(params)) 
            return SendClientMessage(playerid, red, "Syntax Error: /say [text].");
        
        return SendClientMessageToAll(grey, params);
    } 
    return SendLevelErrorMessage(playerid, "say");
}