I still have some difficulty in finding appropriate synonyms. Thank you very much for your previous post.

1) Since his murder, his sister Donatella has taken over (synonym) as the head of design and she has kept up (synonym) the flamboyant (??) nature of collections.
2) Penelope Cruz is a dream come true (synonym) for Mango. She not only designs clothes for celebrities but also jeans and knits (synonym) for more casual daywear (synonym).
3) The celebrity-fashion mix (synonym) is hot (??) right now with Kate Moss designing a capsule (?) collection for Topshop and Madonna enganged by H&M.
4) This was a first venture into (synonym) clothing for Penelope Cruz.
5)Her clothes are based on vintage pieces (synonym) from her own wardrobe and this year will include three distinctive themes: evening dresses for every occasion, retro-marine (??? Synonym) combined with romantic floral pieces, and a more “ad lib” (??) Californian line.

The problem you're having with finding synonyms is that you're looking for synonyms for idioms or phrasal verbs, not for single words.

Try finding alternate phrasing in these collections first. Then let me know if you are still having problems.

http://www.eslcafe.com/idioms/id-mngs.html

http://www.eslcafe.com/pv/

http://grammar.ccc.commnet.edu/grammar/verbs.htm#phrasal

http://www.usingenglish.com/reference/idioms/

http://www.usingenglish.com/reference/phrasal-verbs/

For example, "take over" is a phrasal verb (a verb and a preposition or adverb that takes on an idiomatic meaning). Find it here, alphabetically, and then adjust your sentence:
http://www.usingenglish.com/reference/phrasal-verbs/t.html

Let me know what you come up with.

1) For the first sentence, an appropriate synonym for "taken over" could be "assumed" or "stepped into" as the head of design. As for "kept up," you can use synonyms like "maintained," "sustained," or "preserved" to convey the idea that she continued the flamboyant nature of the collections.

2) In the second sentence, a possible synonym for "dream come true" could be "perfect" or "ideal." For "jeans and knits," you can use synonyms such as "casual attire" or "everyday wear."

3) For the third sentence, a synonym for "celebrity-fashion mix" could be "celebrity-fashion fusion" or "celebrity-fashion collaboration." As for "hot," you can use alternatives like "trendy," "popular," or "in demand." The term "capsule collection" refers to a limited edition or a curated selection, so you can use synonyms like "limited line" or "exclusive assortment."

4) The fourth sentence can be rephrased by using synonyms like "initial foray," "first foray," or "initial endeavor."

5) In the last sentence, "vintage pieces" can be replaced with synonyms such as "retro garments" or "classic attire." For "retro-marine," you can use alternatives like "nautical-inspired" or "naval-themed." "Ad lib" can be substituted with synonyms like "improvised" or "spontaneous."

Remember, when searching for synonyms, it's helpful to use online resources like a thesaurus or a synonym finder. These tools will provide you with various alternatives for each word, allowing you to choose the most appropriate synonym based on context.