That looks to be a combination of inferior grade tape, malfunctioning/inferior recording VCR/camera heads, and lack of flying erase head.
What brand/make of tape is this?
Give not just brand, but any sub-branding.
(For example, not just JVC, but JVC EHG. Doubting this is a JVC tape, of course -- those were good tapes!)
This is good example of why consumer grade VHS tapes should never have been re-used.
Of course, nobody ever listened to that -- not even me. (Stupid, stupid, stupid! Oh well, live and learn.)
I've seen this before, though often in much worse condition. You're actually lucky that it's still this good.
I'd have to refer to my trusty VCR tech manual
("a VCR Bible", if ever there was one), but based from an educated guess, I'd say part of the "still there" old signal is a situation created by different recording modes, combined with narrowed recording heads, then played back on a deck with wider playback heads. So part of the old signal still exists.
The red/blue noise is purely chroma errors caused by lack of flying erase head. It's bleed-through from prior recordings. Remember VHS is a color-under analog signal recording.
The other tape quality issues are likely from self-destruction of the tape on second use. Re-recording wasn't part of the planned use of consumer VHS tapes. It's not much different than writing on paper, erasing it, writing again, erasing again. You'll notice the paper's quality is all shot. The cheaper the paper, the quicker it goes. For example, construction paper or news print, vs thick laser/inkjet stock. I remember writing on "Big Chief" tablets in elementary school. One mistake, and that eraser ate a hole through the paper.
I did a quick Google search for "Big Chief tablet", and came across this blog: http://www.ddranchwear.com/blog/2010...chief-tablets/
This quote gave me a chuckle:
I loved Big Chief tablets. Well…truth is, I loved them except when I had to make a correction and my eraser eroded the paper and it got all nappy.
Apparently they quit making them more than a decade ago. We're all sad for nostalgic reasons, but the paper was truly crappy.
Not much different from many VHS tapes of the 1990s. (1970s-80s tapes were generally much better made.)