Learn Hardcore Japanese: kanozyo ha sinpin wo uketotta bakari da kedo, iro ga awazu, henkin wo eranda. - She had just received the new item, but the color didn’t match, so she chose a refund.

は in 彼女は marks the topic: as for her.
を in 新品を marks the direct object of 受け取った.
が in 色が marks the grammatical subject of the intransitive verb 合う.
を in 返金を marks the direct object of 選んだ. The topic 彼女 carries over to the later clauses, so it’s omitted there but still understood as the subject of 選んだ.

Why is it 受け取ったばかりだ if it means “has just received”?

Past plain form + ばかり expresses a recent completion, and だ states the current resultant situation. So 受け取ったばかりだ = she is in the state of having just received it. It’s about the present state after a very recent past event, not a simple past tense statement.

What’s the difference between 〜たばかり and 〜たところ?

〜たばかり: recently did; subjective and a bit vague about how recent.
Example nuance: it might be minutes or even hours ago, depending on context.
〜たところ: just did; more objective and typically very immediate.
When modifying a noun, 〜たばかりの means “just-VERBed (N).”
Example: 受け取ったばかりの新品 = a brand-new item she just received.

Why is there a だ before けど? Could I say 受け取ったばかりけど?

You need the copula because ばかり here forms a nominal phrase. So you use 受け取ったばかりだ + けど to link to the next clause: 受け取ったばかりだけど.
Alternatives:

受け取ったばかりで、… (link with で)
受け取ったばかりなんだけど、… (with explanatory の)
Polite: 受け取ったばかりですが、…

Could I use のに instead of けど? What’s the nuance difference?

けど: neutral “but/although,” mild contrast.
のに: stronger concessive “even though,” often implying surprise, regret, or frustration.
Using のに here would emphasize the mismatch as unexpectedly disappointing: 受け取ったばかりなのに、色が合わず…

What exactly does 色が合う mean, and why が?

合う is an intransitive verb meaning “to match/fit/suit,” so the thing that matches is marked with が. Common patterns:

Nが合う: The N matches.
Example: 色が合う (the color matches)
AとBが合う: A and B go well together.
Example: 赤と黒が合う
Nに合う: Something suits/works with N.
Example: このシャツは彼女に合う

What is the 〜ず form in 合わず? How is it different from 合わなくて or 合わないで?

〜ず is a formal/written negative connective, roughly like “not doing and…” or “and since it didn’t…”.

合わず: concise, a bit literary; often implies a reason or sequence.
合わなくて: more conversational; also often indicates a reason/cause.
合わないで: “without matching” (purely non-occurrence), less natural here for giving a reason.
In this sentence, 色が合わず、返金を選んだ neatly means “the color didn’t match, so she chose a refund.”

Can I say 色が合わなくて instead of 色が合わず?

Yes. It becomes more conversational:

彼女は新品を受け取ったばかりだけど、色が合わなくて、返金を選んだ。 You could also use an explicit reason connector:
色が合わなかったので、返金を選んだ。 (politer/explanatory)

Is 返金を選んだ natural? What are alternatives?

Yes, it’s natural when choosing among store options like 交換 (exchange) vs 返金 (refund). Alternatives:

返金を希望した: she requested a refund (polite/neutral).
返金を求めた: she demanded/asked for a refund (stronger).
返品して返金してもらった: she returned it and got a refund (explicit process). Use the one that matches the situation and tone.

What’s the difference between 新品 and 新しい?

新品: brand-new, unused product (retail term).
Example: 新品のスマホ
新しい: new to you/recently made, but not necessarily unused.
Example: 新しいスマホ (could be used but new to the owner)
In this sentence, 新品 emphasizes it was a brand-new item.

Why 受け取る and not もらう or 届く?

受け取る: to receive/accept something that is handed or delivered (focus on the act of taking delivery).
もらう: to get/receive from someone (focus on benefitting; often marks the giver with に/から).
届く: to arrive (intransitive; the item arrives, without focusing on the recipient’s act).
Here 受け取る fits a delivery or pickup context.

Can I replace けど with だが or けれど(も)?

Yes; they differ in register:

だが: formal/written.
Example: 受け取ったばかりだが、色が合わず…
けれど / けれども: more formal/politer than けど.
Example: 受け取ったばかりけれど、…
けど: most casual/neutral speech connective in everyday use.

Are the spaces between words normal in Japanese?

No. Japanese normally doesn’t use spaces between words. A natural version is:

彼女は新品を受け取ったばかりだけど、色が合わず、返金を選んだ。

Who is the understood subject of 選んだ, and what doesn’t the color match?

The subject remains 彼女 by topic continuation. 色が合わず is intentionally elliptical; it can mean:

The item’s color doesn’t match her or her style: 彼女に色が合わず…
The color doesn’t match what she expected: 思っていた色と合わず…
It doesn’t match other items: 手持ちの服の色と合わず… Japanese often omits this when context makes it clear.

How would I make the whole sentence more polite?

彼女は新品を受け取ったばかりですが、色が合わず、返金を選びました。
If you want an explicit reason connector:
彼女は新品を受け取ったばかりですが、色が合わなかったので、返金を選びました。