How to control many LEDs with a Shift Register and a single in-line resistor

I am starting to design a Raspberry Pi project that involves several (possibly about 8 to 16) LEDs, of different colours and forward voltages. I may need some, or even all of them illuminated at the same time.

I have found a couple of references that suggest using a 74HC595 Shift Register:

docs.sunfounder.com/projects/newton-lab-kit/en/latest/cproject/ar_74hc595_led.html

learn.pimoroni.com/article/the-shift-register-170pt

The Pimoroni reference mentions a SIL (single in-line) resistor package, without giving any details. I have been unable to find any guidance about using a SIL with multiple LEDs.

This is the design I have in mind, but I would prefer to eliminate some of the resistors. (Diagram copied from the SunFounder reference).

Main question:
Can anybody provide details of how to replace the 8 separate resistors with a SIL, and of what specification?

Other question (if you feel this belongs in a separate question, please let me know):

Both pages imply that I can power green and blue LEDs with 3.3V. Those I possess have a forward voltage of 3.3V. Could I use the 5V pin (or even an external battery) for the power supply?

The design is not at an advanced stage, so other suggestions are welcome. I need to keep about 16 to 20 GPIO pins for other purposes.

Thanks for any suggestions.