Sins of the Fathers Chapter 8: The Ultimate Slayer - S3-E8
Factual error: Despite being a paraplegic, when Smythe is about to be lowered into the vat of chemicals, his legs are pretty toned and muscular. The show implies that Smythe had been wheelchair-bound for a long time, so even if he had muscular legs prior to his paralysis, the muscles would have atrophied.
Sins of the Fathers Chapter 8: The Ultimate Slayer - S3-E8
Other mistake: When Kingpin is berating Smythe over his failure to kill Spider-Man, the camera footage Kingpin is showing of Spider-Man is merely clips from previous episodes.
Answer: I believe it was just a way to try and show the suit is "oily" or reflective. It also helps define the character's features since otherwise, he'd just be a flat black color. It's similar to how the black suit Spidey had blue outlines. (I don't know why they chose a pink/red color... maybe because red is associated with power/fire/war, so it's a more "evil" color?)
TedStixon