Ibanez INF3 and INF4 Wiring help. What is the blue wire?

[Metalshepherd]

I am trying to install two humbuckers in an SG-style guitar. I have a prewired 1 Vol 1 Tone 1 3-way toggle. The wires are BLACK, RED, WHITE, BLUE AND BARE 

[curtisa]

Comparison chart on this page may help, about a quarter way do down the page:

https://awtfy.com/2014/06/19/changing-the-pickups-in-an-ibanez-s420-guitar/

In a nutshell:

• Red = Hot
• Black + White = Tie together and insulate
• Blue + Bare = Ground