Here is another LED If vs Vf graph.

 

LEDnique shows forward voltage curves of different color LEDs but has no date on it.
1) The yellow voltage is higher than I have ever seen.
2) The green voltage is the old style low voltage for dim green LEDs, not the very bright modern green that has the same voltage as blue LEDs.
3) The blue voltage is lower than I have ever seen, a blue LED is in a white LED that has a yellowish phosphor on top so the blue voltage should be the same as white.

 

How did we end up with an 'incorrect' graph?

What makes you think it's "incorrect"? I took it from the manufacturer's datasheet:

 

Where is a Cree yellow LED? They have a "PC Amber" color that I never heard of so I looked for it in Google. It is an LED replacement for an (orange) low pressure sodium lamp. It ain't yellow.

In a local park/trail near my home they recently replaced the dim orange low pressure sodium light bubs with pure white LED lights that are Way Too Bright. To scare away (or attract) coyotes?

 

The circuit drawing calls out LM317L devices. You need to verify that they can handle the power dissipation, voltage across the LM317 x the load current of 700 mA. That may not work for those "L" series packages.