kono dansyoku ha utukusii.

A natural reading is:

• この = kono
• 暖色 = danshoku
• は = written ha but pronounced wa here because it is a particle
• 美しい = utsukushii

So the whole sentence is read:

kono danshoku wa utsukushii

この means this when it comes directly before a noun.

• この暖色 = this warm color
• これ = this one / this thing

So:

• この暖色は美しい。 = This warm color is beautiful.
• これは美しい。 = This is beautiful.

A very common beginner point is:

• この + noun
• これ by itself

You cannot say この alone here.

暖色 means warm color or warm colors, especially in an art/design sense. It refers to colors in the warm range, such as red, orange, and yellow.

A few useful points:

• 暖 = warm
• 色 = color

So the compound literally means something like warm-color.

It can sound a little more technical or art-related than a basic everyday word like 色.

The particle は marks the topic of the sentence.

So この暖色は means something like:

• As for this warm color, ...
• This warm color, ...

Then 美しい tells you something about that topic:

• This warm color is beautiful.

In beginner-friendly terms, は is often the particle used for X is Y type sentences, but more exactly it marks what the sentence is talking about.

Yes, この暖色が美しい。 is grammatically possible, but the nuance changes.

• は: talks about this warm color as the topic
• が: puts more focus on this warm color itself, often as the specific thing that is beautiful

Very roughly:

• この暖色は美しい。 = This warm color is beautiful.
• この暖色が美しい。 = This warm color is the beautiful one / This warm color is what is beautiful.

For learners, は is the more neutral choice if you are just making a simple statement.

Because 美しい is an い-adjective, and い-adjectives can end a sentence by themselves.

So both of these are correct:

• この暖色は美しい。 = plain style
• この暖色は美しいです。 = polite style

Unlike a noun or a な-adjective, an い-adjective does not need だ or です to function as the predicate.

Compare:

• 美しい。 = It is beautiful.
• きれいだ。 / きれいです。 = It is pretty/clean.

That is because 美しい and きれい belong to different grammatical categories.

Yes. 美しい is an い-adjective.

You can tell because it ends in -い, and here it directly describes the topic:

• この暖色は美しい。 = This warm color is beautiful.

Some useful forms:

• dictionary/plain non-past: 美しい
• negative: 美しくない
• past: 美しかった
• adverb form: 美しく

So yes, it behaves like a normal い-adjective grammatically, even though its meaning may feel a little more formal or literary than some other common adjectives.

Because Japanese does not always need an equivalent of English is.

In this sentence, 美しい already works as the predicate:

• この暖色は美しい。
• literally: As for this warm color, beautiful

In natural English, we must say is beautiful, but in Japanese the adjective itself can finish the sentence.

A copula like だ or です is used with nouns and な-adjectives, but not required with い-adjectives like 美しい.

Yes, it is grammatical and understandable. However, it can sound a bit formal, artistic, or written, depending on context.

Why?

• 暖色 is a somewhat technical or category-based word
• 美しい can sound more elegant or literary than everyday きれい

In casual daily conversation, someone might also say:

• この色はきれい。
• この暖かい感じの色はきれい。
• この暖色はきれいです。

So the original sentence is fine, but it may sound more like a description in art, design, or formal commentary than relaxed everyday chat.

Japanese nouns usually do not mark singular vs. plural the way English nouns do.

So 暖色 can refer to:

• a warm color
• warm colors
• the category of warm colors

The exact meaning depends on context.

In この暖色は美しい。, most learners will naturally interpret it as this warm color is beautiful, because この points to a specific thing. But Japanese itself does not force a singular/plural distinction here in the same way English does.

That’s right: normal Japanese writing usually does not use spaces between words.

So the standard written form would be:

この暖色は美しい。

Spaces are often added in beginner materials to make it easier to see the parts:

• この
• 暖色
• は
• 美しい

So the spaces here are just a learning aid, not standard orthography.

Yes, it can. Grammatically, この + noun is perfectly normal, and 暖色 is a noun.

So:

• この暖色 = this warm color

What may feel slightly unusual is not the grammar, but the vocabulary choice. 暖色 refers to a color category, so in some contexts it may sound a bit abstract, like saying this warm-toned color or this warm hue in English.

Still, it is completely valid Japanese.

Both can be translated as beautiful, but they do not feel exactly the same.

• 美しい often sounds more elegant, refined, or literary
• きれい is very common in everyday speech and can also mean pretty or clean

So:

• この暖色は美しい。 sounds a bit elevated or artistic
• この暖色はきれいです。 sounds more ordinary and conversational

Neither is wrong. The choice depends on tone.