"His jacket is pink."
Translation:Jego kurtka jest różowa.
I thought that after jest we shouldn't use the nominative case. For example jesteś kobietą. Could someone explain please?
The difference is that 'różowa' here is an adjective and the structure you're referring to applies to two nouns ( noun [nominative] jest noun [instrumental] ).
Adjectives on the other hand take the form of the noun they are applied to - here it's 'kurtka'. You could say, for example 'Jego kurtka jest różową szmatą' - 'His jacket is a pink rag' - in this example 'pink' refers to 'rag' and takes the instrumental case. I hope it's not too confusing.
Without checking I would say "yes", but I checked and apparently there is something called "żakiet" that men can wear: https://pl.wikipedia.org/wiki/%C5%BBakiet_(str%C3%B3j_m%C4%99ski)
However, Wikipedia claims that its English equivalent is "morning dress" or "formal day dress" o.O