There is a short circuit and the Arduino goes into safety mode.

Some lines in the code don't have $$ ; $$ so an error in the compiler is triggered

The code compiles but nothing happens

The code compiles and the blue light comes on but not the red light.

The code compiles and the red light comes on but not the blue light.

Code compiles and both red and blue lights are on

The code compiles, both lights should light up but only the red light does.

The code compiles, both lights should light up but only the blue light does.