Designing around Output pin limitations
If you know the forward voltage of the LEDs you can easily do some calculations.

For a typical red LED the forward voltage is around 2V.  Other colours vary.  So we can work out that, at 5V supply, each LED with its own 150R resistor, would take:

     V    5-2
I = --- = --- = 20mA
     R    150


With 11 LEDs in parallel on at once that would be 0.02 * 11 = 220mA.

That is far more than the 25mA an IO pin is able to supply, so you will damage the Arduino doing it like that.

Instead you will need to switch each chain of LEDs with a transistor of some form.  I'd choose a logic-level N-channel MOSFET as a "low-side" switch:







simulate this circuit &ndash; Schematic created using CircuitLab

Now your Arduino doesn't care about the current - all it sees is the MOSFET.

If your LED forward voltages are less than 2.5V you can also chain them together to halve the current:







simulate this circuit

Since the forward voltage is now double you use a smaller resistance to set the current (R=V/I, where V is 5-2Vf).