Дочка хочет закрасить фон синей гуашью.

Both mean daughter, but дочка is more everyday, warm, and affectionate.

• дочь = the basic, more neutral word
• дочка = a common affectionate form, like daughter / little daughter / my girl depending on context

In normal spoken Russian, дочка is very common.

This is a very standard Russian pattern:

• хотеть
  • infinitive = to want to do something

So:

• хочет = wants
• закрасить = to paint over / to cover with paint

Together, хочет закрасить means wants to paint over.

Закрасить usually means to cover something with paint, to paint over, or to fill in with color so that what was there is hidden or covered.

That is a little different from:

• красить = to paint in a general sense
• покрасить = to paint something, often emphasizing the completed result
• закрасить = to paint over / cover up with paint

So here the idea is not just painting the background, but covering/filling the background with blue gouache.

Because the sentence focuses on a complete result.

Russian often uses the perfective infinitive after хотеть when the speaker means to do something successfully / to completion.

So:

• хочет красить would sound more like wants to be painting / wants to paint in general
• хочет закрасить means wants to paint it over completely

The perfective verb fits the idea of finishing the background.

Фон is the direct object of закрасить, so it is in the accusative case.

But for a masculine inanimate noun like фон, the accusative singular looks exactly like the nominative singular:

• nominative: фон
• accusative: фон

So the form does not change, even though the case does.

Because this phrase expresses the material or means used to do the painting, and Russian commonly uses the instrumental case for that.

So:

• гуашь = nominative
• гуашью = instrumental, meaning with gouache
• синей agrees with гуашью in case, gender, and number

So синей гуашью means with blue gouache.

Because the adjective must agree with гуашью, which is:

• feminine
• singular
• instrumental

The adjective синий changes like this:

• masculine: синий
• feminine: синяя
• feminine instrumental: синей

So:

• синяя гуашь = blue gouache as the subject/basic dictionary-style phrase
• синей гуашью = with blue gouache

Because гуашь is a feminine noun, and here it is in the instrumental singular.

This noun belongs to the group of feminine nouns ending in a soft sign ь. Their instrumental singular often ends in -ью.

So:

• nominative: гуашь
• instrumental: гуашью

That gives the meaning with gouache.

Yes. Гуашь means gouache, the thick opaque water-based paint often used by children, students, and artists.

It is a feminine noun in Russian:

• эта гуашь = this gouache

So the sentence sounds natural in an art or school context.

Here фон means background.

It is often used in:

• art
• design
• photography
• visual descriptions

So закрасить фон means to paint/fill in the background.

Yes. Russian word order is flexible, though the basic meaning stays the same.

The original order:

• Дочка хочет закрасить фон синей гуашью.

This is neutral and natural.

Other possible orders:

• Дочка хочет синей гуашью закрасить фон.
• Синей гуашью дочка хочет закрасить фон.
• Фон дочка хочет закрасить синей гуашью.

These versions shift the emphasis:

• starting with синей гуашью emphasizes the paint
• starting with фон emphasizes the background

The stress is:

• дОчка
• хОчeт
• закрАсить
• фон
• сИней
• гуАшью

A rough pronunciation guide:

• DOCH-ka KHO-chet za-KRA-sit fon SI-nei goo-Ash-yu

A couple of notes:

• ч in дочка sounds like ch
• х in хочет is the throaty Russian kh
• ю in гуашью helps produce the -shyu ending

Yes. хочет закрасить usually means she wants to do it; it does not say she has already begun.

It describes:

• intention
• desire
• plan

If you wanted to say she is already doing it, you would need a different structure, for example with a present-tense verb of painting.

Yes, the sentence sounds natural in a creative or child-related setting.

The combination suggests:

• дочка = affectionate, everyday tone
• хочет = desire or plan
• закрасить = cover/fill in completely
• фон = the background area
• синей гуашью = using blue gouache as the medium

So the overall feeling is something like: the daughter wants to fill or cover the background with blue paint.