Yes, си́ній is used for darker shades blue, and блаки́тний or голуби́й is for lighter, like Russian си́ний and голубо́й.
(Блаки́тний and голуби́й mean roughly the same thing. But блаки́тний is not used as an euphemism for 'gay', only голуби́й has this meaning, like Russian голубо́й.)
In literary Ukrainian, they don't mean the same thing. Хустка is 'kerchief', шарф is 'scarf'.
Хустка is usually square, or of similar proportions. It's usually thinner compared to шарф:
Хустка can be either wrapped around neck or around head. It's usually worn by women, and it often has complex colourful designs.
Шарф is narrow, and can often be quite thick:
Шарф can only be wrapped around neck. It's worn both by women and men.
(What I've written above is about the literary Ukrainian, based on Central Ukrainian dialects. The word usage might differ in other dialects.)
Дякую Шерая Жаба за випростування! :) We call a "scarf" a "шалик" which both men, women, boys & girls wear. A "хустка", you are correct, is a woman's kerchief. I have never heard of a scarf being called a "шарф" before. Sounds too Anglicized. I wish we'd use proper Ukrainian terms instead of 'borrowing' from other cultures. Ukrainian IS a rich language with its own words that we do not need to be borrowing words from others. :/ I wish Duolingo realized that a fixes these 'verbal glitches'.
Actually, «шарф» is the most used word for 'scarf' in Ukraine. (I don't think it comes from English directly, probably from Russian.) Duolingo teaches Ukrainian as spoken in Ukraine. If you come to any Ukrainian website, you'll see this word. Here are a few examples:
This is actually the most used word in Ukraine. You can search for «інтернет-магазин одягу» in Google, and see what words they use. They will most likely use the words from this course.
So, this is not a mistake. It is really the most used word in Ukraine. The course teaches Ukrainian as spoken in Ukraine.
More specifically, it teaches literary Ukrainian. Ukraine is big, and people in different places speak different varieties of Ukrainian, different dialects. But a unified version of Ukrainian is used on TV, for most books and magazines. This variety of Ukrainian is called the literary Ukrainian, and it similar to the dialects spoken in Central Ukraine (most notably Kiev).
«Шалик» is used only by people in the Western Ukraine. But even they would replace it with «шарф» when writing to people in other regions, because «шарф» is the word used in the literary language.
If you think that the literary Ukrainian should borrow less, this course is no place to change this. This course teaches the language as it is spoken. If you want people to use «шалик» instead of «шарф», you should change the way people speak, not change this course. You might try to talk to people composing dictionaries, or start writing books in your version of Ukrainian (so that it becomes more popular and people start to imitate you), or encourage people to change their language in other ways...
Either way, this is outside of the scope of this course. This course is not for teaching the 'right' Ukrainian, it's for teaching the Ukrainian as used in Ukraine. If «шарф» is used in Ukraine (as you can see by browsing through the online shops), then this course teaches «шарф».
Дякую за відповідь! FYI, I am NOT trying to 'change the course'. That's not what I'm here for. (You & others are doing a WONDERFUL JOB in keeping it up!)
I just would like to see less 'borrowed' words and more authentic words used in the Ukrainian language.
I AM using 'the way we speak' Ukrainian &/or 'literary' Ukrainian. I'm just keeping the ancestor's words 'alive' today. As I love and respect them and the language. And I would hope others would too if they choose to do so.
Let's not exaggerate how much Ukraine "borrows" from Russian while having its own "pure" word. Шалик is not Ukrainian any more than шарф is because szalik (pronounced "шалік") is the Polish word for "scarf"! So, much of the non-Russian, so-called "pure" Ukrainian is just plain Polish.
Well, I guess the word is an 'international word': 'шалик' (Ukr.); 'szalik' (Pol.); 'scarf' (Eng.); 'шарф' (Russ./Ukr.); 'schal' (Germ.); 'шал' (Bulg.); 'šal' (Hr./Croatian, Boznian); 'šátek' (Czech); 'écharpe' (French); 'sciarpa' (Ital.); 'echarpe' (Span.); ... Etc. Etc. Linguistics is very fascinating indeed!
The context is incorrect for simple present tense. It implies habitual or abstract action. "I look for a blue scarf every week." But the Ukrainian sentence in this exercise is more commonly a statement about the current moment rather than habitual and concrete rather than abstract. This requires the present continuous tense in English.