The phrase to see red is an idiom. It means to be upset or angry.
The writer was upset because s/he wasn't able to see the leaves turn red.If it's possible to see red about not seeing red, that is what I was doing. We had misjudged the timing of our autumn trip to see the changing leaves in the Great Lakes states, and I was really upset. No matter how I strained my eyes, I couldn't spot red anywhere.
When some people are stressed, they tense their neck and shoulder muscles. That kind of tension results in muscle spasms (warning stabs)on the upper part of the back, between the shoulders.By the second day I could feel the tension send warning stabs between my shoulder blades.
The writer says, "this vacation was a complete waste." S/he is upset/stressed that the vacation plans did not go as planned.
Fool's gold looks like real gold but it's not. People are fooled by its gold color, but they are happy when they find it. Fool's gold makes people feel lucky!A stone glimmering with fool's gold?
The writer didn't feel lucky on this vacation. S/he thought she would see the leaves turn colors--thought she would be lucky on this vacation, but s/he wasn't lucky.

Student or Learner