Paul Bettany was painted blue as opposed to his normal red because the blue worked better on the black-and-white filters used.
The Stark toaster makes the same sound as when the Iron Man suit powers down.
Vision not knowing what the company actually does is a reference to the many undefined jobs sitcom (and radio show) husbands had for decades.
The suit and wedding dress worn by Vision and Wanda in the opening titles were specifically tailored for the series, with the dress created as an homage to Audrey Hepburn.
Not only was "the boss is coming to dinner" a standard plot in sitcoms until the 1960s, it was also a plot of comedy radio shows before television. The wife not knowing was almost always a part of the set-up as well.