[AndreT]

That must be caused by the return in your loop! In your case anything isn't necessary there. Although you could do it like this:

pawn Code:

for(new i = 0; i < MAX_PLAYERS; i++)
{
    if(!IsPlayerConnected(i) || gTeam[i] == gTeam[playerid]) continue;
    SetPlayerMarkerForPlayer(playerid, i, 0xFFFFFF00);
}