Flag color question

[Wolfram]

I spot a small merchant & line myself up for the intercept and wait submerged till she is real close.

She gets about 800m I make a final check of her colors - the flag definitely has a "union jack" and I refer to my ship recognition book; for I had never seen what almost looked like a British naval "union jack" (red on white) on a blue field with 4 red stars. Only was a guess it was New Zealand and that either:

a) I am have a bad book; on manual on my game New Zealand is red background, white stars

b) I have some strange GPU/card issue

c) having a bad day and I was seeing things

So question is do I have a bad manual or just getting bad graphics?

TIA