They were originally in color. Also, they weren’t released for TV initially. These shorts were released in theaters, similar to how the trailers in modern screenings are released today. It was only in the '50s when these shorts were broadcast on TV.
Over half or slightly more were in black-and-white at the time, that didn’t mean that color films didn’t exist. Even ignoring Technicolor, there were color film experiments and even some feature films. Some films were even only partially in color (Rio Rita '29 is a good example).
At this point in 1942, Technicolor was important enough for filmgoers to not see color films as constituting a very tiny minority of films released.
And yes, these shorts were shown together with black-and-white films as well.
Jerry manages to get Tom evicted from the house. He is happy at first, but he soon finds himself bored without his nemesis, so the two team up to get Tom welcomed back inside.
Tom is dressed up and treated like a baby by the little girl of the house, and he hates it aside from the bottle of milk, that is. Jerry brings in some alley cats, who tease Tom.
Tom inherits $1,000,000 from an eccentric aunt on the condition that he not harm any living thing - even a mouse. And guess which mouse keeps following him around and pointing this out to him?