What I ought to mention as nobody has picked up on it yet, the ATtiny85 doesn't have enough I/O pins to do what you want. It only have 5 pins which means you could only have 3 LEDs if you used 2 pins for communication.
It is possible to disable the Reset pin and gain an extra I/O pin which would allow you to have 4 LEDs, however this requires either a High voltage programmer or a bootloader (The latter of which takes up 576bytes of flash).