Translation:I want a red shirt instead of a blue one.
I agree, "I wish a red shirt..." is frankly incorrect in UK spoken English unless you wish the red shirt to do or be something something like " I wish a red shirt was included in the special offer" in which case you are not wishing to have a red shirt as I assume the Romanian here means. On another note altogether I was always taught that I want never gets and that i should always express any wishes or requests for things whether at home or in shops or restaurants as: "I would like..." This DL does not accept as a translation here which leads me to wonder does Romanian have a polite form like this and like the French voudrais as opposed to veux... As it impacts the apparent politeness of foreigners speaking English it would be sensible for DL to teach the polite form early if there is one.
If Star Trek taught us anything (and it hasn't) is that redshirts are always the first to die. I would take that blue shirt if I were you :-D