When the LCD cracks on a samsung phone it is very likely for it to not show any display afterwards. Phone is probably still on as you said the LED light is showing those colors indicated that it has booted and is displaying notification lights.
Try getting someone or make a call to the phone and see if the phone responds. If it does then the screen needs to be replaced.
If you want you can replace the screen yourself:
You can buy the replacement screen from here:
[product|IF302-000]
Guide to replace the screen:
[guide|44657]
If you do decide to replace the screen, be very careful particularly near both the bottom touch capacitive buttons, you gotta make sure they are separated well from the screen (adhesive must not be sticking to the glass when removing screen)