new RainbowVehicle; sub new sarmale acolo =))
RainbowVehicle = 0; la onplayerconnect
comanda
CMD:rainbowveh(playerid, params[]) {
    if(!IsPlayerInAnyVehicle(playerid)) return SendClientMessage(playerid, COLOR_GREY, "You are not in a vehicle.");
    if(PlayerInfo[playerid][pVIP] == 0) return SendClientMessage(playerid, COLOR_ADV, AdminOnly);
    if(RainbowVehicle)
    {
    	KillTimer(RainbowVehicle);
    	RainbowVehicle = 0;
    	SendClientMessage(playerid, COLOR_LIGHTGREEN3, "(Rainbow Car Status): {FFFFFF}Disable");
   	}
    else
    {
        RainbowVehicle = SetTimerEx("ChangeVehicleRainbow", 500, 1, "i", playerid);
        SendClientMessage(playerid, COLOR_LIGHTGREEN3, "(Rainbow Car Status): {FFFFFF}Enable");
    }
    return 1;
}
asta o adaugi sub function ce vrei tu
function ChangeVehicleRainbow(playerid)
{
    new vehicleid = GetPlayerVehicleID(playerid);
    ChangeVehicleColor(vehicleid, random(256), random(256));
}