kono dansyoku to kansyoku no haisyoku ha kodomo ppoi.

A natural reading is:

この だんしょく と かんしょく の はいしょく は こどもっぽい。

A few notes:

• 暖色 = だんしょく (warm colors)
• 寒色 = かんしょく (cool colors)
• 配色 = はいしょく (color scheme / color arrangement)
• 子供っぽい = こどもっぽい (childish / childlike-looking)

Notice that 子供 and っぽい are pronounced together smoothly as こどもっぽい.

It means something like:

a color scheme using warm colors and cool colors

Here is the structure:

• 暖色 = warm colors
• と = and
• 寒色 = cool colors
• の = linking particle, similar to of
• 配色 = color scheme / color combination

So:

• 暖色と寒色の配色
• literally: the color scheme of warm colors and cool colors
• more naturally in English: a warm-and-cool color scheme or a color scheme combining warm and cool colors

The particle の connects nouns.

In this sentence:

• 暖色と寒色 = warm colors and cool colors
• 暖色と寒色の配色 = the color scheme of warm and cool colors

So の turns the first noun phrase into something that modifies 配色.

You can think of it as similar to:

• 日本の車 = Japanese cars / cars of Japan
• 春の服 = spring clothes
• 暖色と寒色の配色 = a warm-and-cool color scheme

と connects nouns and means and.

So:

• 暖色と寒色 = warm colors and cool colors

This is the standard way to join two nouns in Japanese.

The は marks the topic of the sentence.

So the sentence is talking about:

この暖色と寒色の配色 = this warm-and-cool color scheme

Then it comments on that topic:

子供っぽい = childish / looks childlike

So the whole structure is:

• [Topic] は [comment]
• この暖色と寒色の配色は 子供っぽい。
• As for this warm-and-cool color scheme, it looks childish.

Use この when a noun comes right after it.

• この配色 = this color scheme
• この暖色と寒色の配色 = this warm-and-cool color scheme

Use これ when the word stands alone.

• これは子供っぽい。 = This is childish.

So:

• この + noun
• これ by itself

〜っぽい often means seems like, has the feel of, or kind of like.

So 子供っぽい means:

• childish
• childlike
• having a child-like feel

It is often slightly negative, especially when used for design, behavior, or taste, because it suggests something is immature or unsophisticated.

For example:

• 子供っぽい服 = childish clothes
• 子供っぽい言い方 = a childish way of speaking

However, depending on context, it can sometimes be softer and just mean playful or youthful.

This is a very useful distinction.

• 子供っぽい = childish, immature-looking, childlike in a possibly negative way
• 子供らしい = childlike in a natural, appropriate, or positive way

So if you say:

• 子供っぽい配色
  it suggests the color scheme feels immature or unsophisticated

But:

• 子供らしい配色
  would suggest a color scheme that is suitably childlike, maybe bright, innocent, or fitting for children

So っぽい often carries a more subjective or critical nuance than らしい.

Because 子供っぽい is a single adjective-like expression built from:

• 子供
  • っぽい

The っぽい attaches directly to the noun.

Examples:

• 水っぽい = watery
• 油っぽい = oily
• 大人っぽい = mature-looking / adult-like
• 子供っぽい = childish

So you do not insert a particle between the noun and っぽい.

Yes. っぽい behaves like an い-adjective.

So you can conjugate it like other い-adjectives:

• 子供っぽい = childish
• 子供っぽくない = not childish
• 子供っぽかった = was childish
• 子供っぽくて = childish, and...
• 子供っぽさ = childishness

That makes 子供っぽい very useful and flexible.

Because 子供っぽい is an い-adjective, and い-adjectives can end a sentence by themselves.

So:

• この配色は子供っぽい。
• literally: This color scheme is childish.

There is no need to add です in plain style.

If you want a more polite version, you can say:

• この暖色と寒色の配色は子供っぽいです。

Not usually in this sentence.

配色 specifically refers to:

• color arrangement
• color combination
• color scheme

It is about how colors are used together, not just the colors themselves.

So here, color scheme or color combination is the best translation.

It modifies the whole noun phrase that follows.

So:

• この暖色と寒色の配色
• this [warm-and-cool color scheme]

It does not mean just this warm color.

If it only modified 暖色, the structure and meaning would feel different.

Yes, absolutely.

• この配色は子供っぽい。 = This color scheme is childish.

The original sentence includes 暖色と寒色の to specify what kind of color scheme it is.

So the longer version is more descriptive:

• この暖色と寒色の配色は子供っぽい。
• This warm-and-cool color scheme looks childish.

Yes, here it is read こども.

In modern Japanese, you may see several spellings:

• 子供
• 子ども
• こども

They are all read こども.

The differences are mostly about writing style, formality, or editorial preference, not pronunciation.

The pattern is:

この + noun phrase + は + adjective

More specifically:

• この暖色と寒色の配色 = this warm-and-cool color scheme
• は = topic marker
• 子供っぽい = is childish / looks childish

So the sentence is a very common Japanese structure:

• [topic] は [description]

Examples of the same pattern:

• この服は派手だ。 = These clothes are flashy.
• このデザインは古い。 = This design is old.
• この配色は子供っぽい。 = This color scheme is childish.

It is in the plain style because it ends with 子供っぽい and does not use です.

Plain:

• この暖色と寒色の配色は子供っぽい。

Polite:

• この暖色と寒色の配色は子供っぽいです。

The meaning is basically the same; the difference is tone and level of formality.