[[L3th4l]]

pawn Код:

public OnPlayerCommandText(playerid, cmdtext[])
{
    if(strcmp(cmdtext, "/paint", true) == 0) 
    {
        if(!IsPlayerInAnyVehicle(playerid)) return SendClientMessage(playerid, 0xFFFFF, "You must be in a vehicle!");

        return ChangeVehicleColor(GetPlayerVehicleID(playerid), random(255), random(255));
    }
    return 0;
}

Add that or replace it if you already have "OnPlayerCommandText"
Also delete the previous command.