Individual selectivity of LED matrix
Matrix designs are almost always meant to be multiplexed.  Whether using switches as inputs or LEDs as output.  This means the matrix is (usually) checked or driven one intersection (where a row and column come together) at a time.

In the example schematic there are 3 LEDs (Red, Green &amp; Blue) at each intersection.  As stated above, the matrix is driven (usually) one intersection at a time. To light the LEDs at intersection 2.2 the row 2 line would be driven high and the column 2 lines would be driven low.  

To expedite the process, for this particular design, it is possible to light all desired LEDs in a given column or in a given row.  But not both!

You should concern your self with current limiting resistors where needed.  Also with LED power requirements and the impact of lighting multiple LED on your power supply.